UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 11-K
(Mark one)

      [X] ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE
ACT OF 1934

                   For the fiscal year ended December 31, 2004

                                       OR

      [ ] TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES
EXCHANGE ACT OF 1934

                  For the transition period from _____ to ____

                         Commission file number 0-20388

      A. Full title of the plan and the address of the plan, if different from
that of the issuer named below:

                      LITTELFUSE, INC. 401(K) SAVINGS PLAN

      B. Name of issuer of the securities held pursuant to the plan and the
address of its principal executive office.

                                Littelfuse, Inc.
                            800 E. Northwest Highway
                           Des Plaines, Illinois 60016



FINANCIAL STATEMENTS AND SUPPLEMENTAL SCHEDULE

Littelfuse, Inc. 401(k) Savings Plan
Years Ended December 31, 2004 and 2003



                      Littelfuse, Inc. 401(k) Savings Plan

                              Financial Statements
                            and Supplemental Schedule

                     Years Ended December 31, 2004 and 2003

                                    CONTENTS


                                                                         
Report of Independent Registered Public Accounting Firm.................    1

Financial Statements

Statements of Assets Available for Benefits.............................    2
Statements of Changes in Assets Available for Benefits..................    3
Notes to Financial Statements...........................................    4

Supplemental Schedule

Schedule H, Line 4i - Schedule of Assets (Held at End of Year)..........    8




             Report of Independent Registered Public Accounting Firm

Plan Management
Littelfuse, Inc. 401(k) Savings Plan

We have audited the accompanying statements of assets available for benefits of
the Littelfuse, Inc. 401(k) Savings Plan as of December 31, 2004 and 2003, and
the related statements of changes in assets available for benefits for the years
then ended. These financial statements are the responsibility of the Plan's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.

We conducted our audits in accordance with the standards of the Public Company
Accounting Oversight Board (United States). Those standards require that we plan
and perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement. We were not engaged to perform an
audit of the Plan's internal control over financial reporting. Our audits
included consideration of internal control over financial reporting as a basis
for designing audit procedures that are appropriate in the circumstances, but
not for the purpose of expressing an opinion on the effectiveness of the Plan's
internal control over financial reporting. Accordingly, we express no such
opinion. An audit also includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements, assessing the
accounting principles used and significant estimates made by management, and
evaluating the overall financial statement presentation. We believe that our
audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the assets available for benefits of the Plan at December
31, 2004 and 2003, and the changes in assets available for benefits for the
years then ended, in conformity with U.S. generally accepted accounting
principles.

Our audits were performed for the purpose of forming an opinion on the financial
statements taken as a whole. The accompanying supplemental schedule of assets
(held at end of year) as of December 31, 2004, is presented for purposes of
additional analysis and is not a required part of the financial statements, but
is supplementary information required by the Department of Labor's Rules and
Regulations for Reporting and Disclosure under the Employee Retirement Income
Security Act of 1974. This supplemental schedule is the responsibility of the
Plan's management. The supplemental schedule has been subjected to the auditing
procedures applied in our audits of the financial statements and, in our
opinion, is fairly stated in all material respects in relation to the financial
statements taken as a whole.

                                                           /s/ ERNST & YOUNG LLP
                                                               ERNST & YOUNG LLP

May 24, 2005
Chicago, Illinois

                                                                               1


                      Littelfuse, Inc. 401(k) Savings Plan

                          Notes to Financial Statements

                     Years Ended December 31, 2004 and 2003

                      Littelfuse, Inc. 401(k) Savings Plan

                   Statements of Assets Available for Benefits



                                                      DECEMBER 31
                                                  2004          2003
                                               -----------  ------------
                                                      
Investments, at fair value                     $40,447,468  $ 34,385,444
Cash                                                15,644             -
Contributions receivable:
   Participant                                           -        20,461
   Employer                                         55,376         6,123
                                               -----------  ------------
Assets available for benefits                  $40,518,488  $ 34,412,028
                                               ===========  ============


See accompanying notes.

                                                                               4


                      Littelfuse, Inc. 401(k) Savings Plan

                    Notes to Financial Statements (continued)

                      Littelfuse, Inc. 401(k) Savings Plan

             Statements of Changes in Assets Available for Benefits



                                                               YEARS ENDED DECEMBER 31
                                                                2004           2003
                                                             -----------   ------------
                                                                     
ADDITIONS

Employer contributions                                       $   765,094   $    551,793
Participant contributions                                      2,763,729      2,085,557
Rollover contributions                                           253,190      3,719,532
Interest and dividends                                           799,101        443,511
                                                             -----------   ------------
Total additions                                                4,581,114      6,800,393

DEDUCTIONS

Distributions to participants                                  1,897,009      2,730,618

Net realized and unrealized appreciation
   in fair value of investments                                3,422,355      5,893,495
                                                             -----------   ------------
Net increase                                                   6,106,460      9,963,270
Assets available for benefits at beginning of year            34,412,028     24,448,758
                                                             -----------   ------------
Assets available for benefits at end of year                 $40,518,488   $ 34,412,028
                                                             ===========   ============


See accompanying notes.

                                                                               5


                      Littelfuse, Inc. 401(k) Savings Plan

                    Notes to Financial Statements (continued)

1. DESCRIPTION OF THE PLAN

The following description of the Littelfuse, Inc. 401(k) Savings Plan (Plan)
provides general information only. Reference should be made to the Summary Plan
Description or the Plan document for more complete information.

The Plan is a defined-contribution, profit-sharing plan, which is optional to
all eligible employees of Littelfuse, Inc. (Company). The Plan is administered
by the T. Rowe Price Trust Company (Trustee) under the direction of the plan
administrator. The Plan is subject to the provisions of the Employee Retirement
Income Security Act of 1974 (ERISA).

All employees of the Company who have completed 90 days of service are eligible
to participate in the Plan. Effective July 1, 2003, the Company purchased the
Teccor Electronics, Inc. (Teccor). At that time, employees of Teccor became
eligible to participate in the Plan and could rollover any previous account
balance into the Plan.

Participants may elect to contribute up to 23% of their annual pretax
compensation, subject to certain limitations. Highly compensated participants,
as defined by the Internal Revenue Service (IRS), are subject to more
restrictive maximum limits. The Company matches participant contributions 50
cents on the dollar up to the first 4% of the participant's compensation, as
defined.

Participants are immediately vested in their contributions and earnings thereon.
Participants become 100% vested in their Company contributions after two years
of service.

A participant may direct employee and Company contributions in any of 11
investment options.

Each participant's account is credited with the participant's contributions and
allocations of: (a) the Company's contributions, and (b) Plan earnings.
Allocations are based on participant earnings or account balances, as defined.
Forfeited balances of terminated participants' nonvested accounts are used to
reduce future Company contributions. The benefit to which a participant is
entitled is the benefit that can be provided from the participant's account.

Participants are entitled to receive a distribution of their accounts upon
reaching age 59 1/2, termination of employment, disability, death, or in the
event of a financial hardship. Distributions may be made in a lump sum or in
periodic installments and are taxable to the participant when received.
Distributions prior to 59 1/2 may subject the participant to a 10% federal
income tax penalty.


                                                                               6


                      Littelfuse, Inc. 401(k) Savings Plan

                    Notes to Financial Statements (continued)

1. DESCRIPTION OF THE PLAN (CONTINUED)

Loans are available to eligible participants, bearing interest at a rate
commensurate with rates that may be obtained on similar borrowings in the normal
course of business. Participants may borrow from their Plan account in
accordance with provisions of the Plan.

Although it has not expressed an intent to do so, the Company has the right
under the Plan to terminate the Plan subject to the provisions of ERISA. In the
event of Plan termination, participants will become 100% vested in their
accounts.

2. SIGNIFICANT ACCOUNTING POLICIES

INVESTMENT VALUATION AND INCOME RECOGNITION

The investments of the Plan are stated at fair value. The shares of registered
investment companies are valued at quoted market prices, which represent the net
asset values of shares held by the Plan at year-end. Securities traded on a
national securities exchange are valued at the last reported sales price on the
last business day of the Plan year. Participant loans are stated at cost, which
approximates fair value.

Purchases and sales of securities are recorded on a trade-date basis. Interest
income is recorded on the accrual basis. Dividends are recorded on the
ex-dividend date.

DISTRIBUTIONS

Distributions to participants are recorded by the Plan when actual payments are
made.

USE OF ESTIMATES

The preparation of financial statements in conformity with U.S. generally
accepted accounting principles requires management to make estimates and
assumptions that affect the amounts reported in the financial statements and
accompanying notes. Actual results could differ from those estimates.

                                                                               7


                      Littelfuse, Inc. 401(k) Savings Plan

                    Notes to Financial Statements (continued)

3. INVESTMENTS

The fair value of individual investments that represent 5% or more of the Plan's
assets is as follows:



                                                           DECEMBER 31
                                                       2004          2003
                                                    ----------    ----------
                                                            
T. Rowe Price Prime Reserve Fund                    $4,587,971    $4,491,920
T. Rowe Price Equity Income Fund                     7,064,681     6,152,915
T. Rowe Price Growth Stock Fund                      8,047,085     7,353,251
T. Rowe Price New Horizons Fund                      4,813,525     4,223,875
T. Rowe Price Equity Index 500 Fund                  3,308,107     2,794,418
T. Rowe Price New Income Fund                        3,255,618     2,855,473
Littelfuse, Inc. common stock                        2,425,558     2,056,474


During 2004 and 2003, the Plan's investments (including investments purchased,
sold, as well as held during the year) appreciated in fair value as follows:



                                                       2004          2003
                                                    ----------    ----------
                                                            
Registered investment companies                     $3,030,156    $5,118,492
Littelfuse, Inc. common stock                          392,199       775,003
                                                    ----------    ----------
                                                    $3,422,355    $5,893,495
                                                    ==========    ==========


4. INCOME TAX STATUS

The underlying nonstandardized prototype plan has received an opinion letter
from the IRS dated February 27, 2002, stating that the form of the Plan is
qualified under Section 401 of the Internal Revenue Code (Code) and, therefore,
the related trust is tax-exempt. In accordance with Revenue Procedure 2002-6 and
Announcement 2001-77, the Plan Sponsor has determined that it is eligible to and
has chosen to rely on the current IRS prototype plan opinion letter. Once
qualified, the Plan is required to operate in conformity with the code to
maintain its qualification. The plan administrator believes the Plan is being
operated in compliance with the applicable requirements of the Code and,
therefore, believes that the Plan is qualified and the related trust is
tax-exempt.

                                                                               8


                      Littelfuse, Inc. 401(k) Savings Plan

                    Notes to Financial Statements (continued)

5. ADMINISTRATIVE EXPENSES

All administrative fees of the Plan are paid by the Company. Certain accounting
and legal expenses are paid by the Company on behalf of the Plan.

6. RISK AND UNCERTAINTIES

The Plan invests in various investment securities. Investment securities are
exposed to various risks such as interest rate, market, and credit risks. Due to
the level of risk associated with certain investment securities, it is at least
reasonably possible that changes in the values of investment securities will
occur in the near term and that such changes could materially affect
participants' account balances and the amounts reported in the statements of
assets available for benefits.

7. SUBSEQUENT EVENT

Effective January 1, 2005, the maximum contribution deferral percentage was
increased to 90%.

                                                                              9


                              Supplemental Schedule
                      Littelfuse, Inc. 401(k) Savings Plan

                    Schedule H, Line 4i - Schedule of Assets
                              (Held at End of Year)

                            EIN #36-3795742 Plan #002

                                December 31, 2004



   IDENTITY OF                                                      NUMBER       CURRENT
     ISSUER                         DESCRIPTION                   OF SHARES       VALUE
-----------------       ------------------------------------      ---------   ------------
                                                                     
T. Rowe Price*          Prime Reserve Fund                        4,587,971   $  4,587,971
T. Rowe Price*          New Income Fund                             357,367      3,255,618
T. Rowe Price*          Equity Income Fund                          265,689      7,064,681
T. Rowe Price*          Growth Stock Fund                           301,728      8,047,085
T. Rowe Price*          New Horizons Fund                           164,621      4,813,525
T. Rowe Price*          International Stock Fund                     94,675      1,224,153
T. Rowe Price*          Equity Index 500 Fund                       101,600      3,308,107
T. Rowe Price*          Mid-Cap Value Fund                           67,542      1,552,782
T. Rowe Price*          Small-Cap Value Fund                         45,423      1,621,756
T. Rowe Price*          Mid-Cap Growth Fund                          29,640      1,478,446
Littelfuse, Inc.*       Common stock                                 71,006      2,425,558
Participant loans       Loans receivable with varying
                           maturities; interest rate ranging
                           from 5% to 10.5%                                      1,067,786
                                                                              ------------
                                                                              $ 40,447,468
                                                                              ============


* Indicates party in interest to the Plan.


                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the 
trustees (or other persons who administrate the employee benefit plan) have 
duly caused this annual report to be signed on its behalf by the undersigned 
hereunto duly authorized.


                                  Littelfuse, Inc.
                                  Littelfuse, Inc. 401(K) Savings Plan
                                  

Dated: June 29, 2005              By: /s/ Paul M. Dickinson
                                     --------------------------------------
                                     Paul M. Dickinson
                                     Vice President & Treasurer
                                     Plan Administrator


Dated: June 29, 2005              By: /s/ Kenneth R. Audino  
                                     --------------------------------------
                                     Kenneth R. Audino
                                     Vice President, Organizational
                                     Development & Total Quality Management
                                     Plan Administrator


            Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement on
Form S-8 (No. 333-03260) pertaining to the Littelfuse, Inc. 401(k) Savings Plan,
of our report dated May 24, 2005, with respect to the financial statements and
supplemental schedule of the Littelfuse, Inc. 401(k) Savings Plan included in
this Annual Report (Form 11-K) for the year ended December 31, 2004.

                                                           /s/ ERNST & YOUNG LLP
                                                               ERNST & YOUNG LLP

Chicago, Illinois
June 24, 2005