Exhibit 10.1



AGREEMENT OF SUBSTITUTION AND AMENDMENT OF

COMMON STOCK RIGHTS AGREEMENT



This Agreement of Substitution and Amendment is entered into as of February 14, 2003, by and between
Millipore Corporation, a Massachusetts corporation (the Company) and American Stock Transfer and Trust Company, a New York banking corporation (AST).



RECITALS



|A. |  | On April 16, 1998 the Company entered into a Common Stock Rights Agreement (the Rights Agreement) with The First National Bank of Boston (subsequently
Equiserve Trust Company, N.A.) (the Predecessor Agent) as rights agent.
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|B. |  | The Company wishes to remove the Predecessor Agent and substitute AST as rights agent pursuant to Section 21 of the Rights Agreement.
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|C. |  | The Company has given the Predecessor Agent notice of removal of the Predecessor Agent as rights agent.
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AGREEMENT



NOW THEREFORE, in consideration of the foregoing and of other consideration, the sufficiency of which
is hereby acknowledged, the parties agree as follows:



|1. |  | Section 21 of the Rights Agreement is hereby amended to provide that any successor rights agent shall, at the time of its appointment as rights agent, have a
combined capital and surplus of at least $10 million, rather than $50 million.
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|2. |  | The Company hereby appoints AST as rights agent pursuant to Section 21 of the Rights Agreement, to serve in that capacity for the consideration and subject to all of
the terms and conditions of the Rights Agreement.
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|3. |  | AST hereby accepts the appointment as rights agent pursuant to Section 21 of the Rights Agreement and agrees to serve in that capacity for the consideration and
subject to all of the terms and conditions of the Rights Agreement.
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|4. |  | From and after the effective date hereof, each and every reference in the Rights Agreement to a Rights Agent shall be deemed to be a reference to AST.
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|5. |  | Section 26 of the Rights Agreement is amended to provide that notices or demands shall be addressed as follows (until another address is filed):
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|If to the Company: |  | MILLIPORE CORPORATION                  
|------------------ |  | ---------------------------------------
|                   |  | 290 Concord Road                       
|                   |  | Billerica, MA 01821-3405               
|                   |  | Attention: General Counsel             
|                  
|with a copy to:    |  | David B. Walek                         
|                   |  | Ropes & Gray                           
|                   |  | One International Place                
|                   |  | Boston, MA 02110-2624                  
|                  
|If to AST:         |  | American Stock Transfer & Trust Company
|                   |  | 59 Maiden Lane                         
|                   |  | New York, NY 10038                     
|                   |  | Attention: Corporate Trust Department  



|6. |  | Except as expressly modified herein, the Right Agreement shall remain in full force and effect.
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|7. |  | This Agreement of Substitution and Amendment may be executed in one or more counterparts, each of which shall together constitute one and the same document.
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IN WITNESS WHEREOF, the
parties have caused this Agreement to be duly executed as of the date first above written:



MILLIPORE CORPORATIONBy:

/s/    JEFFREY
RUDINJeffrey Rudin




AMERICAN STOCK TRANSFER & TRUST
COMPANYBy:

/s/    HERBERT J.
LEMMERHERBERT J. LEMMER VICE PRESIDENT