Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
LEVY KENNETH
   2. Issuer Name and Ticker or Trading Symbol
KLA TENCOR CORP [KLAC] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chairman of the Board
(Last)
(First)
(Middle)
C/O KLA-TENCOR CORPORATION, 160 RIO ROBLES		 3. Date of Earliest Transaction (Month/Day/Year)
12/15/2004
(Street)

SAN JOSE, CA 95130		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 12/15/2004   M   25,000 A $ 10.81 25,762 D  
Common Stock 12/15/2004   S   25,000 D $ 46.9809 762 D  
Common Stock               1,719,375 I by Levy Fam. Trust (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Non-Qualified Stock Option (right to buy) $ 10.81 12/15/2004   M     25,000 10/07/1997 10/08/2006 Common Stock 25,000 $ 46.9809 75,000 D  
Non-Qualified Stock Option (right to buy) $ 10.63             08/31/1999 08/31/2008 Common Stock 204,272   204,272 D  
Non-Qualified Stock Option (right to buy) $ 16.97             10/23/1999 10/23/2008 Common Stock 220,728   220,728 D  
Non-Qualified Stock Option (right to buy) $ 26.25             11/10/2001 11/10/2010 Common Stock 18,951   18,951 D  
Non-Qualified Stock Option (right to buy) $ 29.31             10/02/2002 10/02/2011 Common Stock 28,425   28,425 D  
Non-Qualified Stock Option (right to buy) $ 32.75             04/04/2002 04/04/2011 Common Stock 18,951   18,951 D  
Non-Qualified Stock Option (right to buy) $ 33.75             10/27/2000 10/27/2009 Common Stock 90,000   90,000 D  
Non-Qualified Stock Option (right to buy) $ 34.67             11/08/2003 01/28/2013 Common Stock 15,724   15,724 D  
Non-Qualified Stock Option (right to buy) $ 37.05             11/08/2003 11/08/2012 Common Stock 7,863   7,863 D  
Non-Qualified Stock Option (right to buy) $ 40.66             10/27/2004 08/02/2014 Common Stock 4,500   4,500 D  
Non-Qualified Stock Option (right to buy) $ 41.79             09/21/2005 09/21/2014 Common Stock 50,000   50,000 D  
Non-Qualified Stock Option (right to buy) $ 44.6875             08/13/2000 08/13/2010 Common Stock 37,901   37,901 D  
Non-Qualified Stock Option (right to buy) $ 45.16             10/27/2004 04/26/2014 Common Stock 7,500   7,500 D  
Non-Qualified Stock Option (right to buy) $ 51.229             11/08/2003 07/30/2013 Common Stock 7,863   7,863 D  
Non-Qualified Stock Option (right to buy) $ 53.86             10/27/2004 10/27/2013 Common Stock 12,000   12,000 D  
Non-Qualified Stock Option (right to buy) $ 58.1             10/27/2004 01/27/2014 Common Stock 6,000   6,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
LEVY KENNETH
C/O KLA-TENCOR CORPORATION
160 RIO ROBLES
SAN JOSE, CA 95130		   X     Chairman of the Board  

Signatures

 By: Stuart J. Nichols For: Kenneth Levy   12/15/2004
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Due to an administrative error, the number of securities beneficially owned by the reporting person was reported incorrectly on the original Form 4.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

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