1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 (AMENDMENT NO. ____2____)* STERIS CORP COM - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (Name of Issuer) Common Stock - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (Title of Class of Securities) 859152100 - - - - - - - - - - - - - (CUSIP Number) *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). 2 Cusip No. 859152100 - - - - - - - 13G ____________________________________________________________________________ 1. NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON State of Wisconsin Investment Board 39-6006423 ____________________________________________________________________________ 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP * (a)____ Not Applicable (b)____ ____________________________________________________________________________ 3. SEC USE ONLY ____________________________________________________________________________ 4. CITZENSHIP OR PLACE OF ORGANIZATION Madison, Wisconsin ____________________________________________________________________________ NUMBERS OF 5. SOLE VOTING POWER SHARES 7,420,200 BENEFICIALLY __________________________________________________________ OWNED BY 6. SHARED VOTING POWER EACH Not Applicable REPORTING __________________________________________________________ PERSON 7. SOLE DISPOSITIVE POWER WITH 7,420,200 __________________________________________________________ 8. SHARED DISPOSITIVE POWER Not Applicable ____________________________________________________________________________ 9. AGGREGATE AMOUNT BENEFICALLY OWNED BY EACH REPORTING PERSON 7,420,200 ____________________________________________________________________________ 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES * Not Applicable ____________________________________________________________________________ 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 10.70 ____________________________________________________________________________ 12. TYPE OF REPORTING PERSON * EP (Public Pension Fund) ____________________________________________________________________________ * SEE INSTRUCTIONS BEFORE FILLING OUT! 3 ITEM 1. ISSUER (a) STERIS CORP COM (b) 5960 Heisley Road Mentor, OH 44060 USA ITEM 2. PERSON FILING (a) State of Wisconsin Investment Board (b) P.O. Box 7842 Madison, WI 53707 (c) Wisconsin State Agency (d) See cover page (e) See cover page ITEM 3. THIS STATEMENT IS FILED PURSUANT TO 13d-1(b) or 13d-2(b) AND THE STATE OF WISCONSIN INVESTMENT BOARD IS A GOVERNMENT AGENCY WHICH MANAGES PUBLIC PENSION FUNDS SUBJECT TO PROVISIONS COMPARABLE TO ERISA. ITEM 4. OWNERSHIP (a) See Row 9 on Page 2 (b) See Row 11 on Page 2 (c) The State of Wisconsin Investment Board retains sole voting and dispositive power for all shares. ITEM 5. IF THIS STATEMENT IS BEING FILED TO REPORT THE FACT THAT AS OF THE DATE HEREOF THE REPORTING PERSON HAS CEASED TO BE THE BENEFICIAL OWNER OF MORE THAN FIVE PERCENT OF THE CLASS OF SECURITIES, CHECK THE FOLLOWING _____. ITEM 6. NOT APPLICABLE ITEM 7. NOT APPLICABLE ITEM 8. NOT APPLICABLE ITEM 9. NOT APPLICABLE ITEM 10. CERTIFICATION By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purpose or effect. SIGNATURE After reasonable inquiry to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. February 15, 2002 - - - - - - - - - - Date /s/ Jean Ledford - - - - - - - - - Signature Jean Ledford, Chief Investment Officer - Public Equities - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Name/Title