United States
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G   

Under the Securities Exchange Act of 1934

(Amendment No. __)*

Name of Issuer - K L A Instruments Corp.

Title or Class of Securities - Common Stock

CUSIP Number - 482480100

Check the following box if a fee is being paid with this
statement [ X ].


<PAGE>
Cusip No. 482480100

Page 2 of 10 Pages

1.  Name of Reporting Person
    (S.S. or I.R.S. Identification No. of above person)

Twentieth Century Companies, Inc. - 43-1325032

2.  Check the appropriate box if a member of a group* - N/A

3.  SEC Use Only

4.  Citizenship or place of organization

Maryland

5.  Sole voting power

1,230,000

6.  Shared voting power

0

7.  Sole dispositive power

1,230,000

8.  Shared dispositive power

0

9.  Aggregate amount beneficially owned by each reporting person

1,230,000

10.  Check box if the aggregate amount in Row (9) excludes
certain shares - 

N/A

11.  Percent of class represented by amount in Row 9

5.3%

12.  Type of reporting person*

HC


<PAGE>
Cusip No. 482480100

Page 3 of 10 Pages

1.  Name of Reporting Person
    (S.S. or I.R.S. Identification No. of above person)

Investors Research Corporation - 44-0640487

2.  Check the appropriate box if a member of a group* - N/A

3.  SEC Use Only

4.  Citizenship or place of organization

Delaware

5.  Sole voting power

1,230,000

6.  Shared voting power

0

7.  Sole dispositive power

1,230,000

8.  Shared dispositive power

0

9.  Aggregate amount beneficially owned by each reporting person

1,230,000

10.  Check box if the aggregate amount in Row (9) excludes
certain shares -

N/A

11.  Percent of class represented by amount in Row 9

5.3%

12.  Type of reporting person*

IA


<PAGE>
Cusip No. 482480100

Page 4 of 10 Pages

1.  Name of Reporting Person
    (S.S. or I.R.S. Identification No. of above person)

Twentieth Century Investors, Inc. - 44-6006315

2.  Check the appropriate box if a member of a group* - N/A

3.  SEC Use Only

4.  Citizenship or place of organization

Maryland

5.  Sole voting power

1,230,000

6.  Shared voting power

0

7.  Sole dispositive power

1,230,000

8.  Shared dispositive power

0

9.  Aggregate amount beneficially owned by each reporting person

1,230,000

10.  Check box if the aggregate amount in Row (9) excludes
certain shares -

N/A

11.  Percent of class represented by amount in Row 9

5.3%

12.  Type of reporting person*

IV


<PAGE>
Cusip No. 482480100

Page 5 of 10 Pages

1.  Name of Reporting Person
    (S.S. or I.R.S. Identification No. of above person)

James E. Stowers, Jr. - 492-38-8397

2.  Check the appropriate box if a member of a group* - N/A

3.  SEC Use Only

4.  Citizenship or place of organization

United States

5.  Sole voting power

1,230,000

6.  Shared voting power

0

7.  Sole dispositive power

1,230,000

8.  Shared dispositive power

0

9.  Aggregate amount beneficially owned by each reporting person

1,230,000

10.  Check box if the aggregate amount in Row (9) excludes
certain shares -

N/A

11.  Percent of class represented by amount in Row 9

5.3%

12.  Type of reporting person*

IN



<PAGE>    
SCHEDULE 13G

Item 1(a).     NAME OF ISSUER

     K L A Instruments Corp.

Item 1(b).     ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES

     160 Rio Robles
     San Jose, CA  95134

Item 2(a).   NAME OF PERSONS FILING

     Twentieth Century Companies, Inc., on its behalf and on
behalf of:

     Investors Research Corporation
     Twentieth Century Investors, Inc.
     James E. Stowers, Jr.

Item 2(b).   ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE,  
              RESIDENCE

     4500 Main Street, P.O. Box 418210, Kansas City, MO 64141-
     9210  Attn:  David H. Reinmiller

Item 2(c).   CITIZENSHIP

Maryland

Item 2(d).   TITLE OF CLASS OF SECURITIES

     Common Stock

Item 2(e).     CUSIP NO.

     482480100

Item 3.   IF THIS STATEMENT IS FILED PURSUANT TO RULES 13d-
           1(b) OR 13d-2(b), CHECK WHETHER THE PERSON FILING IS A

     g [ X ]   Parent Holding Company, in accordance with        
               Rule 13d-1(b)(ii)(G) (Note:  See Item 7).

Item 4.   OWNERSHIP

     (a)  Aggregate amount beneficially owned:

          1,230,000

     (b)  Percent of class:
          
          5.3%
         
     (c)  Number of shares as to which such person has:

          (i)  sole power to vote or to direct the vote:
               1,230,000

          (ii) shared power to vote or to direct the vote:
               0

          (iii)sole power to dispose or to direct the
               disposition of: 1,230,000

          (iv) shared power to dispose or to direct the
               disposition of: 0

Item 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

     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.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF 
          ANOTHER PERSON

     Investors Research Corporation, a registered investment
adviser and a wholly-owned subsidiary of Twentieth Century
Companies, Inc., manages, pursuant to management agreements, the
investments of five registered investment companies, Twentieth
Century Investors, Inc., Twentieth Century World Investors, Inc.,
Twentieth Century Capital Portfolios, Inc., Twentieth Century
Premium Reserves, Inc. and TCI Portfolios, Inc.  It also manages
the assets of institutional investor accounts.  The securities
that are the subject of this report are owned by and held for
such investment companies and separate institutional investor
accounts.  Any dividends received from such securities, or the
proceeds of any sale of such securities, are for the benefit of,
and are held for such investment companies and separate
institutional investor accounts.

     Twentieth Century Investors, Inc. owned 1,230,000 shares or
5.3% of the securities that are the subject of this report.

     For further information regarding the ownership of the
securities that are the subject of this report, see Exhibit A
attached hereto.

 Item 7.  IDENTIFICATION AND CLASSIFICATION OF THE                
          SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING         
          REPORTED ON BY THE PARENT HOLDING COMPANY

     See attached Exhibits A and B.

Item 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF     
          THE GROUP

     N/A

Item 9.   NOTICE OF DISSOLUTION OF GROUP

     N/A

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 werenot acquired in
connection with or as a participant in any transaction having
such purpose or effect.


SIGNATURE

     After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.



February 10, 1995               TWENTIETH CENTURY COMPANIES, INC.
      Date    

                                By: /s/ William M. Lyons
                                    William M. Lyons
                                    Executive Vice President




<PAGE>
EXHIBIT A

IDENTITY AND ITEM 3 CLASSIFICATION OF A SUBSIDIARY OF
PARENT HOLDING COMPANIES

     This Schedule 13G is being filed by Twentieth Century
Companies, Inc. ("TCC").  Investors Research Corporation ("IRC"),
an investment advisor registered under Section 203 of the
Investment Advisors Act of 1940, is a wholly-owned subsidiary of
TCC.  Mr. James E. Stowers, Jr., controls TCC by virtue of his
ownership of approximately 60% of the voting stock of TCC.

     As a result of its status as investment advisor to five
investment companies registered under Section 8 of the Investment
Company Act and to several institutional investors, IRC is deemed
to be the beneficial owner of 1,230,000 shares (the "Shares") or
5.3% of the outstanding common stock of K L A Instruments Corp.
(the "Issuer"). 

     TCC, as a result of its control of IRC, and Mr. Stowers, as
a result of his control of TCC, are also deemed to beneficially
own all such shares deemed to be beneficially owned by IRC.  Mr.
Stowers, TCC and IRC all disclaim beneficial ownership of the
Shares.

     The ownership of one investment company client of IRC,
Twentieth Century Investors, Inc. ("TCI"), totalled 1,230,000
shares or 5.3% of the outstanding common stock of the Issuer.

     This Schedule 13G is being filed by TCC on behalf of TCC,
IRC, TCI and Mr. Stowers.



<PAGE>
EXHIBIT B

Rule 13d-1(f)(1)(iii) Agreement


     Each of the undersigned hereby agrees and consents to the
execution and joint filing on its or his behalf by Twentieth
Century Companies, Inc. of this Schedule 13G respecting the
beneficial ownership of the common stock of K L A Instruments
Corp. at December 31, 1994.

     Dated this 10th day of February, 1995.

                                Twentieth Century Companies, Inc.


                                By: /s/ William M. Lyons          
      
                                    William M. Lyons
                                    Executive Vice President


                                Investors Research Corporation


                                By: /s/ William M. Lyons          
      
                                    William M. Lyons
                                    Executive Vice President


                                Twentieth Century Investors, Inc.


                                By: /s/ William M. Lyons          
      
                                    William M. Lyons
                                    Executive Vice President



                                    /s/ James E. Stowers, Jr.     
       
                                    James E. Stowers, Jr.