X0202 4 2007-08-01 0001101302 ENTEGRIS INC ENTG 0001134619 DAUWALTER JAMES E 3250 JULIAN DRIVE CHASKA MN 55318 1 0 0 0 Common Stock 2007-08-01 4 M 0 30000 3.15 A 86175 D Common Stock 2007-08-01 4 S 0 500 10.73 D 85675 D Common Stock 2007-08-01 4 S 0 400 10.74 D 85275 D Common Stock 2007-08-01 4 S 0 200 10.77 D 85075 D Common Stock 2007-08-01 4 S 0 500 10.78 D 84575 D Common Stock 2007-08-01 4 S 0 600 10.80 D 83975 D Common Stock 2007-08-01 4 S 0 800 10.81 D 83175 D Common Stock 2007-08-01 4 S 0 1000 10.82 D 82175 D Common Stock 2007-08-01 4 S 0 400 10.83 D 81775 D Common Stock 2007-08-01 4 S 0 1200 10.84 D 80575 D Common Stock 2007-08-01 4 S 0 2300 10.85 D 78275 D Common Stock 2007-08-01 4 S 0 5400 10.86 D 72875 D Common Stock 2007-08-01 4 S 0 2900 10.87 D 69975 D Common Stock 2007-08-01 4 S 0 600 10.88 D 69375 D Common Stock 2007-08-01 4 S 0 2400 10.89 D 66975 D Common Stock 2007-08-01 4 S 0 1200 10.90 D 65775 D Common Stock 2007-08-01 4 S 0 1400 10.91 D 64375 D Common Stock 2007-08-01 4 S 0 1200 10.92 D 63175 D Common Stock 2007-08-01 4 S 0 200 10.93 D 62975 D Common Stock 2007-08-01 4 S 0 900 10.94 D 62075 D Common Stock 2007-08-01 4 S 0 1800 10.95 D 60275 D Common Stock 2007-08-01 4 S 0 100 10.96 D 60175 D Common Stock 2007-08-01 4 S 0 1000 10.97 D 59175 D Common Stock 2007-08-01 4 S 0 800 10.98 D 58375 D Common Stock 2007-08-01 4 S 0 200 10.99 D 58175 D Common Stock 2007-08-01 4 S 0 1600 11.00 D 56575 D Common Stock 2007-08-01 4 S 0 400 11.01 D 56175 D Common Stock 243621 I By Judith V. Dauwalter Rev. Trust UA 12/11/2001 Common Stock 118719 I By James E. Dauwalter Rev. Trust UA 12/11/2001 Common Stock 96666 I By James E. Dauwalter Irrev. Trust UA 4/10/2000 Employee Stock Option (Right to Buy) 3.15 2007-08-01 4 M 0 30000 0 D 2008-12-12 Common Stock 30000 150000 D Indicated sales were effected pursuant to a Rule 10b5-1 Plan adopted by the Reporting Person on September 8, 2006. This option is fully vested. These options were acquired pursuant to an employee stock option plan that provided for the grant of options in consideration of services as an employee. This is the first of two Form 4's. Peter W. Walcott, Attorney-in-Fact for James E. Dauwalter 2007-08-03