EMERSON ELECTRIC CO — Director's Dealing 2006

Aug 14, 2006

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: MKS INSTRUMENTS INC (MKSI)
CIK: 0001049502
Period of Report: 2006-08-10

Reporting Person: EMERSON ELECTRIC CO (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2006-08-10	Common Stock	S	43323	$19.3927	Disposed	4720040	Indirect
2006-08-11	Common Stock	S	12083	$19.1789	Disposed	4707957	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 10, 2006, as follows and as described in
Footnote 2 below: 301 shares at $19.08; 100 at $19.09; 99 at $19.10; 100 at $19.13; 200 at $19.20; 100 at $19.21; 100 at
$19.22; 100 at $19.23; 100 at $19.25; 500 at $19.27; 3,300 at $19.30; 2,900 at $19.31; 3,200 at $19.32; 1,928 at $19.33;
2,473 at $19.34; 847 at $19.35; 2,577 at $19.36; 2,975 at $19.37; 2,200 at $19.38; 2,300 at $19.39; 500 at $19.40; 2,300 at
$19.41; 1,152 at $19.42; 1,351 at $19.43; and 950 at $19.44.

F2: This footnote sets forth additional detail with respect to the transactions described in Footnote 1, as follows: 1,200 shares
at $19.45; 800 at $19.46; 700 at $19.47; 400 at $19.48; 300 at $19.49; 913 at $19.50; 845 at $19.52; 500 at $19.53; 900 at
$19.54; 800 at $19.55; 100 at $19.56; 700 at $19.57; 1,000 at $19.58; 600 at $19.59; 400 at $19.60; 200 at $19.63; and 312
at $19.64. The weighted average sales price for these transactions was $19.3927 per share.

F3: The sales were effected in multiple transactions, at varying prices, on August 11, 2006, as follows: 1,700 shares at $19.00;
800 at $19.01; 100 at $19.02; 103 at $19.03; 226 at $19.04; 200 at $19.08; 400 at $19.10; 194 at $19.11; 144 at $19.12; 100
at $19.13; 456 at $19.14; 1,100 at $19.15; 300 at $19.16; 100 at $19.17; 300 at $19.18; 100 at $19.19; 500 at $19.20; 400 at
$19.22; 400 at $19.23; 160 at $19.25; 100 at $19.26; 100 at $19.28; 2,100 at $19.29; 100 at $19.30; 490 at $19.31; 531 at
$19.32; 296 at $19.35; 200 at $19.36; 100 at $19.37; 100 at $19.41; and 183 at $19.42. The weighted average sales price for
these transactions was $19.1789 per share.