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 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 *
BARNHOLT EDWARD W
   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
_____ Officer (give title below) __X__ Other (specify below)
Chairman of the Board
(Last)
(First)
(Middle)
C/O KLA-TENCOR CORPORATION, ONE TECHNOLOGY DRIVE		 3. Date of Earliest Transaction (Month/Day/Year)
05/02/2012
(Street)

MILPITAS, CA 95035		 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 05/02/2012   M   5,000 A $ 37.05 44,167 I By Trust (1)
Common Stock 05/02/2012   M   5,000 A $ 37.05 49,167 I By Trust (1)
Common Stock 05/02/2012   M   2,500 A $ 51.35 51,667 I By Trust (1)
Common Stock 05/02/2012   M   1,250 A $ 49.99 52,917 I By Trust (1)
Common Stock 05/02/2012   S   13,750 D $ 51.82 (2) 39,167 I By Trust (1)
Common Stock - Restricted Stock Units (3)               3,809 D  

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) $ 37.05 05/02/2012   M     5,000   (4) 11/08/2012 Common Stock 5,000 $ 0 0 D  
Non-Qualified Stock Option (Right to Buy) $ 37.05 05/02/2012   M     5,000   (5) 11/08/2012 Common Stock 5,000 $ 0 0 D  
Non-Qualified Stock Option (Right to Buy) $ 51.35 05/02/2012   M     2,500   (6) 08/02/2012 Common Stock 2,500 $ 0 0 D  
Non-Qualified Stock Option (Right to Buy) $ 49.99 05/02/2012   M     1,250   (7) 11/04/2012 Common Stock 1,250 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BARNHOLT EDWARD W
C/O KLA-TENCOR CORPORATION
ONE TECHNOLOGY DRIVE
MILPITAS, CA 95035		   X     Chairman of the Board

Signatures

 Brian M. Martin as Attorney-in-Fact for Edward W. Barnholt   05/03/2012
**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) By The Barnholt Family Trust dated January 8, 1987, of which the Reporting Person is a trustee and beneficiary.
(2) This transaction was executed in multiple trades at prices ranging from $51.74 to $52.00. The price reported above reflects the weighted average sales price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer, full information regarding the number of shares and prices at which the transaction was effected.
(3) Each restricted stock unit ("RSU") represents a contingent right to receive one share of KLA-Tencor common stock.
(4) The option was granted for 5,000 shares of KLA-Tencor common stock on November 8, 2002 and was immediately exercisable for all of the underlying shares on the date of grant.
(5) The option was granted for 5,000 shares of KLA-Tencor common stock on November 8, 2002 and was immediately exercisable for all of the underlying shares on the date of grant.
(6) The option was granted for 2,500 shares of KLA-Tencor common stock on August 2, 2005 and was immediately exercisable for all of the underlying shares on the date of grant.
(7) The option was granted for 1,250 shares of KLA-Tencor common stock on November 4, 2005 and was immediately exercisable for all of the underlying shares on the date of grant.

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