X0203 3/A 2010-02-24 2010-03-01 0 0001101302 ENTEGRIS INC ENTG 0001485478 Blake Lynn Larson 9728 LAFORET DRIVE EDEN PRAIRIE MN 55347 0 1 0 0 Vice President, Finance, CAO Common Stock 66698 D Common Stock 10000 I By trust with spouse Employee Stock Option (right to buy) 7.07 2015-02-21 Common Stock 19600 D Employee Stock Option (right to buy) 1.13 2016-02-19 Common Stock 72000 D Employee Stock Option (right to buy) 5.40 2017-02-19 Common Stock 29330 D The March 1, 2010 filing on Form 3 is being updated to reflect an overstatement in direct holdings at 25,058 shares. This option is exercisable in three equal annual installments. The first installment became exercisable on 2/21/2009, the second installment became exercisable on 2/21/2010 and the last installment becomes exercisable on 2/21/2011. This option is exercisable in three equal annual installments. The first installment became exercisable on 2/19/2010, the second installment becomes exercisable on 2/19/2011 and the last installment becomes exercisable on 2/19/2012. This option is exercisable in three equal annual installments. The first installment becomes exercisable on 2/19/2011, the second installment becomes exercisable on 2/19/2012 and the last installment becomes exercisable on 2/19/2013. Peter W. Walcott, Attorney-in-Fact for Lynn L. Blake 2010-11-15