EMERSON ELECTRIC CO — Director's Dealing 2006

Aug 4, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-08-02

Reporting Person: EMERSON ELECTRIC CO (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-08-02	Common Stock	S	44940	$20.3263	Disposed	4963745	Indirect
2006-08-03	Common Stock	S	44194	$20.4016	Disposed	4919551	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1065182	Direct

Footnotes

F1: The sales were effected in multiple transactions, at varying prices, on August 2, 2006, as follows and as described in
Footnote 2 below: 300 shares at $20.01; 200 at $20.04; 200 at $20.05; 200 at $20.07; 500 at $20.08; 300 at $20.09; 500 at
$20.10; 100 at $20.11; 300 at $20.13; 300 at $20.14; 100 at $20.15; 600 at $20.16; 200 at $20.18; 1,300 at $20.20; 400 at
$20.21; 500 at $20.22; 1,100 at $20.23; 900 at $20.24; 1,200 at $20.25; 1,900 at $20.26; 3,501 at $20.27; 3,577 at $20.28;
2,422 at $20.29; 1,610 at $20.30; 2,200 at $20.31; 1,300 at $20.32; 1,895 at $20.33; 880 at $20.34; and 800 at $20.35.

F2: This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 1,200
shares at $20.36; 400 at $20.37; 500 at $20.38; 1,400 at $20.39; 1,500 at $20.40; 200 at $20.41; 800 at $20.42; 855 at
$20.43; 1,600 at $20.44; 2,400 at $20.45; 100 at $20.46; 700 at $20.47; 200 at $20.49; 1,100 at $20.52; 100 at $20.53; 100
at $20.55; 548 at $20.57; 552 at $20.58; 400 at $20.59; 300 at $20.60; 400 at $20.61; and 300 at $20.63. The weighted
average sales price for these transactions was $20.3263 per share.

F3: The sales were effected in multiple transactions, at varying prices, on August 3, 2006, as follows and as described in
Footnote 4 below: 100 shares at $19.99; 174 at $20.02; 100 at $20.03; 500 at $20.04; 200 at $20.05; 200 at $20.06; 300 at
$20.08; 600 at $20.09; 300 at $20.10; 260 at $20.11; 40 at $20.12; 400 at $20.13; 326 at $20.14; 888 at $20.15; 1,112 at
$20.16; 1,000 at $20.17; 1,600 at $20.18; 1,000 at $20.19; 500 at $20.20; 100 at $20.21; 800 at $20.22; 200 at $20.23; 600
at $20.24; 900 at $20.25; 1,100 at $20.26; 107 at $20.27; 100 at $20.28; 400 at $20.29; and 400 at $20.30.

F4: This footnote sets forth additional detail with respect to the transactions described in Footnote 3, as follows: 400 shares
at $20.31; 200 at $20.32; 300 at $20.33; 200 at $20.34; 200 at $20.35; 1,700 at $20.41; 500 at $20.42; 300 at $20.43; 100 at
$20.44; 300 at $20.45; 300 at $20.46; 1,000 at $20.47; 4,200 at $20.48; 1,387 at $20.49; 2,800 at $20.50; 800 at $20.51;
1,100 at $20.52; 1,900 at $20.53; 1,900 at $20.54; 1,800 at $20.55; 2,300 at $20.56; 4,100 at $20.57; 1,000 at $20.58; 500
at $20.59; 200 at $20.60; and 400 at $20.61. The weighted average sales price for these transactions was $20.4016 per
share.