SEC FORM 4

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

EMERSON ELECTRIC CO

(Last)

(First)

(Middle)

8000 W. FLORISSANT AVE.

(Street)

ST LOUIS

63136

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
MKS INSTRUMENTS INC [ MKSI ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

Director	X	10% Owner
Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
05/17/2006

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/17/2006		S		39,720	D	$21.662⁽¹⁾⁽²⁾	6,597,571	I	Through a subsidiary⁽³⁾
Common Stock	05/18/2006		S		45,357	D	$21.297⁽⁴⁾⁽⁵⁾	6,552,214	I	Through a subsidiary⁽³⁾
Common Stock								1,065,182	D⁽⁶⁾

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 Securities Underlying Derivative Security (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: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

1. Name and Address of Reporting Person^*

EMERSON ELECTRIC CO

(Last)

(First)

(Middle)

8000 W. FLORISSANT AVE.

(Street)

ST LOUIS

63136

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director	X	10% Owner
Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

ASTEC AMERICA INC

(Last)

(First)

(Middle)

5810 VAN ALLEN WAY

(Street)

CARLSBAD

92008

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director	X	10% Owner
Officer (give title below)		Other (specify below)

Explanation of Responses:

1. The sales were effected in multiple transactions, at varying prices, on May 17, 2006, as follows and as described in Footnotes 2 below: 200 shares at $21.40; 100 at $21.42; 200 at $21.43; 400 at $21.45; 300 at $21.46; 92 at $21.47; 300 at $21.49; 400 at $21.50; 408 at $21.51; 500 at $21.52; 1,492 at $21.53; 730 at $21.54; 739 at $21.55; 1,078 at $21.56; 1,761 at $21.57; 1,100 at $21.58; 582 at $21.59; 200 at $21.60; 1,650 at $21.61; 1,618 at $21.62; 1,180 at $21.63; 1,875 at $21.64; 2,655 at $21.65; 1,850 at $21.66; 1,000 at $21.67; 1,100 at $21.68; 2,200 at $21.69; and 2,400 at $21.70.

2. This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 500 shares at $21.71; 900 at $21.72; 800 at $21.73; 200 at $21.74; 754 at $21.75; 2,100 at $21.76; 1,100 at $21.77; 500 at $21.78; 564 at $21.79; 1,082 at $21.80; 200 at $21.81; 510 at $21.82; 500 at $21.83; 300 at $21.84; 500 at $21.85; 400 at $21.86; 100 at $21.87; 100 at $21.89; 300 at $21.91; and 200 at $21.92. The weighted average sales price for these transactions was $21.6620 per share.

3. The reported securities are owned directly by Astec America Inc. The Reporting Person is the ultimate parent company of Astec America Inc.

4. The sales were effected in multiple transactions, at varying prices, on May 18, 2006, as follows and as described in Footnotes 5 below: 500 shares at $20.83; 600 at $20.84; 3,176 at $20.85; 1,006 at $20.86; 930 at $20.87; 1,170 at $20.88; 100 at $20.89; 1,005 at $20.90; 100 at $20.91; 1,095 at $20.93; 400 at $20.94; 200 at $20.95; 200 at $20.96; 400 at $20.97; 700 at $20.98; 720 at $20.99; 300 at $21.01; 300 at $21.04; 200 at $21.06; 200 at $21.07; 100 at $21.09; 400 at $21.10; 300 at $21.11; 200 at $21.15; 200 at $21.16; 300 at $21.18; 500 at $21.19; and 600 at $21.20.

5. This footnote sets forth additional detail with respect to the transactions described in Footnote 4 as follows: 300 shares at $21.21; 800 at $21.25; 300 at $21.27; 200 at $21.29; 100 at $21.30; 300 at $21.33; 100 at $21.34; 100 at $21.37; 300 at $21.38; 400 at $21.39; 400 at $21.41; 600 at $21.42; 1,100 at $21.43; 500 at $21.44; 800 at $21.45; 1,352 at $21.46; 1,202 at $21.47; 3,300 at $21.48; 4,400 at $21.49; 3,400 at $21.50; 814 at $21.51; 1,500 at $21.52; 1,486 at $21.53; 800 at $21.54; 900 at $21.55; 800 at $21.56; 389 at $21.57; 400 at $21.58; 712 at $21.59; 100 at $21.61; 300 at $21.66; 600 at $21.68; and 700 at $21.69. The weighted average sales price for these transactions was $21.2970 per share.

6. The reported securities are owned directly by Emerson Electric Co.

Remarks:

See Exhibit 99.1 - Joint Filer Information

	/s/ Timothy G. Westman, Assistant Secretary for Emerson Electric Co.	05/19/2006
	/s/ Timothy G. Westman, Secretary for Astec America Inc.	05/19/2006
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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