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 * GEYER STAN   2. Issuer Name and Ticker or Trading Symbol ENTEGRIS INC [ENTG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 3500 LYMAN BOULEVARD 3. Date of Earliest Transaction (Month/Day/Year) 12/06/2004 (Street) CHASKA, MN 55318 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 01/10/2005 01/10/2005 S   404 D $ 8.64 85,584 (1) I by family member Common Stock 01/10/2005 01/10/2005 S   1,100 D $ 8.65 84,484 I by family member Common Stock 01/10/2005 01/10/2005 S   3,496 D $ 8.66 80,988 I by family member Common Stock 12/07/2004 12/07/2004 G V 3,000 D $ 0 170,677 (2) (3) D   Common Stock 01/04/2005 01/04/2005 G V 2,500 D $ 0 31,395 I by Family Foundation Common Stock 01/12/2005 01/12/2005 J(4) V 177 (4) D $ 0 262,397 I by ESOP Common Stock 12/06/2004 12/06/2004 J(5) V 2,400 D $ 0 4,023 (5) I by Chae Industries Common Stock 12/06/2004 12/06/2004 J(1)(3)(5) V 120,000 A $ 0 120,000 I Transend III (6)

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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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
GEYER STAN 3500 LYMAN BOULEVARD CHASKA, MN 55318	X

Signatures

By: /s/ Lori Cameron, Attorney-in-Fact for Stan Geyer		01/12/2005
**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)	Since the reporting person's last report, 58,800 shares held by a family member have been contributed to Transend III.
(2)	Includes 404 shares acquired under the Entegris, Inc stock purchase plan on December 31, 2004
(3)	Since the reporting person's last report, 58,800 shares previously owned directly have been contributed to Transend III.
(4)	177 shares sold by Entegris ESOP Trustee to cover plan administrative expenses.
(5)	Since the reporting person's last report, 2,400 shares held by Chae Industries have been contributed to Transend III.
(6)	This entity was formed as part of a series of transactions for estate planning purposes.

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