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                                   ATMI, INC.

              NON-EMPLOYEE DIRECTORS DEFERRED COMPENSATION PROGRAM
                          OF ATMI, INC. 1998 STOCK PLAN

                                    ARTICLE 1
                                    ---------

                                     GENERAL

1.1   NAME AND PURPOSE.

      The purpose of the Non Employee Directors Deferred Compensation Program
(the "Program") is to provide Awards under the 1998 Stock Plan (the "Plan") of
ATMI, Inc., a Delaware corporation, to Non-Employee Directors of the Company as
a vehicle to defer receipt of all retainers and meeting fees paid to
Non-Employee Directors, and to permit such deferred amounts to be credited to
Stock Accounts, established at the time of each deferral, equivalent to shares
of the Company's Common Stock, at prices contemporaneous with each deferral
date.

1.2   DEFINITIONS.

      Whenever used herein, all capitalized terms not defined herein shall have
the meaning set forth in the Plan and the following terms shall have the meaning
set forth or referenced below;

      (a)   "Board" means the Board of Directors of the Company.

      (b)   "Business Day" means a day except for a Saturday, Sunday or a legal
            holiday in the State of Connecticut.

      (c)   "Common Stock" means (i) the common stock of the Company, adjusted
            as provided in Section 3.5, or (ii) if there is a merger or
            consolidation and the Company is not the surviving corporation
            thereof, the capital stock of the surviving corporation given in
            exchange for such common stock of the Company.

      (d)   "Compensation" means retainer fees for service on, and fees for
            attendance at meetings of, the Board and any committees thereof,
            which are payable to a Non-Employee Director during a Program Year.

      (e)   "Deferral Date" means the last Business Day of each calendar quarter
            during a Program Year.

      (f)   "Non-Employee Director" means any individual serving on the Board
            who is not an employee of the Company or any of its subsidiaries or
            affiliates.

      (g)   "Program" has the meaning set forth in Section 1.1 above.

      (h)   "Program Year" means the calendar year.

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      (i)   "Stock Account" means a bookkeeping account established for each
            Participant pursuant to the terms hereof consisting of Stock
            Credits.

      (j)   "Stock Credit" means a credit to a Stock Account representing shares
            of Common Stock, calculated pursuant to Article 2.

      (k)   "Stockholders' Meeting" means the Annual Meeting of Stockholders of
            the Company.


                                   ARTICLE 2
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                                  FEE DEFERRALS

2.1   ELIGIBILITY.

      Effective beginning on the first day of January 2001, each Non-Employee
Director serving on such date or at any time thereafter shall be eligible to
participate, and shall participate, in the Program.

2.2   GRANT OF STOCK CREDITS.

      Effective on the first day of January 2001, each person who serves as a
Non-Employee Director shall have his or her Stock Account credited with Stock
Credits as herein described. Any person who becomes a Non-Employee Director at
any time thereafter shall have his or her Stock Account credited with Stock
Credits as herein described- Stock Credits with respect to Compensation shall be
established on each Deferral Date in an amount equal to (A) the aggregate
Compensation which would have been paid to such Participant during such calendar
quarter, divided by (B) the Fair Market Value of the Common Stock on the
Deferral Date.

2.3   DIVIDENDS.

      As of the date any dividend is paid to holders of shares of Common Stock,
such Stock Account shall be credited with additional Stock Credits equal to (A)
the amount which would have been paid as dividends on that number of shares
(including fractions of a share) of Common Stock equal to the number of Stock
Credits attributed to such Stock Account on the record date for such dividend
payment, divided by (B) the Fair Market Value of the Common Stock on the
dividend payment date. In the case of dividends paid in property other than
cash, the amount of the dividend shall be deemed to be the fair market value of
the property at the time of the payment of the dividend, as determined in good
faith by the Committee.

                                   ARTICLE 3
                                   ---------

                            DISTRIBUTION OF ACCOUNTS

3.1   TIME AND METHOD OF PAYMENT.

      Distribution of the Stock Account of a Participant shall be made by the
last Business Day of the first calendar month following such Participant's
termination of service as a director of the

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Company. Distribution of a Participant's Stock Account shall be made, subject to
Section 3.4, in a single installment in that number of shares of Common Stock as
is equal to the number of Stock Credits in the Participant's Stock Account on
the date of distribution, except that the value of any fractional share shall be
paid in cash based on the Fair Market Value of the Common Stock on the date of
distribution.

3.2   SEVERE FINANCIAL HARDSHIP.

      Notwithstanding any other Section of this Article 3, at the written
request of a Participant or a Participant's legal representative, the Committee,
in its sole discretion upon a finding that continued deferral will result in
severe financial hardship to the Participant, may authorize the payment of all
or a part of a Participant's Stock Account, subject to Section 3.4, in shares of
Common Stock, in a single installment prior to the distribution date for such
Stock Account under Section 3.1 or Section 3.3. Thereafter, Stock Credits shall
be credited to such Participant's Stock Account in accordance with Section 2.2
or Section 2.3.

3.3   DISTRIBUTION UPON DEATH.

      Notwithstanding any other provision of this Program, upon the death of a
Participant, the Committee shall authorize the Company to distribute, subject to
Section 3.4 hereof, all of such Participant's Stock Account in a single
installment to such person or persons, as the Participant may have designated.
All such designations shall be made in writing and delivered to the Committee. A
Participant may from time to time revoke or change any such designation by
written notice to the Committee. If there is no designation on file with the
Committee at the time of the Participant's death, or if the person or persons
designated therein shall have all predeceased the Participant or otherwise
ceased to exist, or if there is a dispute among designees of a Participant, such
distributions shall be made to the executor or administrator of the
Participant's estate. Any distribution under this Section 3.3 shall be made as
soon as practicable after the Committee is notified of the Participant's death
or is satisfied as to the identity of the appropriate payee, whichever is later.
Such distribution shall be made as provided in the second sentence of Section
3.1.

3.4   WITHHOLDING TAXES.

      If required by any applicable law, the Company shall deduct from all
distributions under the Plan any taxes required to be withheld by federal,
state, or local governments, computed on the basis of the Fair Market Value of
the number of shares of Common Stock otherwise distributable on the date of
distribution.

3.5   ADJUSTMENT OF STOCK ACCOUNTS.

      If at any time the number of outstanding shares of Common Stock shall be
increased as the result of any stock dividend, stock split, subdivision or
reclassification of shares, the number of Stock Credits with which the Stock
Account of each Participant is credited shall be increased in the same
proportion as the outstanding number of shares of Common Stock is increased. If
the number of outstanding shares of Common Stock shall at any time be decreased
as the result of any combination, reverse stock split or reclassification of
shares, the number of Stock Credits with which the Stock Account of each
Participant is credited shall be decreased in the same


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proportion as the outstanding number of shares of Common Stock is decreased. In
the event a dividend in kind is declared having a value per share of Common
Stock equal to 10% or more of the Fair Market Value of a share of Common Stock
on the Business Day prior to the public announcement of such dividend, the
Committee shall make an appropriate equitable adjustment in the number of Stock
Credits with which the Stock Account of each Participant is credited. In the
event the Company shall at any time be consolidated with or merged into any
other corporation and holders of shares of Common Stock receive shares of the
capital stock of the resulting or surviving corporation (or any consideration
other than shares of capital stock), there shall be credited to the Stock
Account of each Participant, in place of the Stock Credits then credited
thereto, new Stock Credits in an amount equal to the product of the number of
shares of capital stock (or consideration other than shares of capital stock)
exchanged for one share of Common Stock upon such consolidation or merger and
the number of Stock Credits with which such Stock Account then is credited.

                                   ARTICLE 4
                                   ---------

                                  THE COMMITTEE

4.1   AUTHORITY.

      The Committee shall have full power and authority to administer the
Program, including the power to (a) promulgate forms to be used with respect to
the Program, (b) promulgate rules of Program administration, (c) settle any
disputes as to rights or benefits arising from the Program, (d) interpret and
construe the terms of the Program, including, but not limited to, determining
entitlement to benefits and the amount of such benefits, and (e) make such
decisions or take such action as the Committee, in its sole discretion, deems
necessary or advisable to aid in the proper administration of the Program. Any
decision made by the Committee shall be final and binding on the Company,
Participants and their heirs or successors. The Committee may delegate its power
and authority to administer the Program to officers and employees of the
Company; provided, however, that the Committee's power and authority under
Section 3.2 (regarding Severe Financial Hardship) shall not be delegated.

4.2   OPERATION.

      The Committee may act (a) by majority vote of its members meeting in
person or by telephone, or (b) by consent in writing signed by all of the
members of the Committee.

4.3   ELECTIONS, NOTICES.

      All elections and notices required to be provided to the Committee under
the Program must be in such form or forms prescribed by, and contain such
information as is required by, the Committee.


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                                   ARTICLE 5
                                   ---------

                                  MISCELLANEOUS

5.1   FUNDING.

      All amounts payable under the Program shall constitute a general unsecured
obligation of the Company.

5.2   NON-ALIENATION OF BENEFITS.

      No benefit under the Program shall be subject in any manner to
anticipation, alienation, sale, transfer, assignment, pledge, encumbrance, or
charge, and any attempt to do so shall be void. No such benefit, prior to
receipt thereof pursuant to the provisions of the Program, shall be in any
manner liable for or subject to the debts, contracts, liabilities, engagements
or torts of the Participant.

5.3   GOVERNING LAW.

      This Program shall be governed by the laws of the State of Connecticut.

5.4   AMENDMENT, MODIFICATION AND TERMINATION OF THE PROGRAM.

      The Board at any time may terminate and in any respect amend or modify the
Program; provided, however, that no such termination, amendment or modification
shall adversely affect the rights of any Participant or beneficiary, including
his or her rights with respect to Stock Credits credited prior to such
termination, amendment or modification, without his or her consent.

5.5   NON-FORFEITURABILITY OF STOCK CREDITS.

      No Stock Credits credited to the Stock Account of a Participant shall be
forfeitable for any reason.

5.6   SUCCESSORS AND HEIRS.

      The Program and any properly executed elections hereunder shall be binding
upon the Company and Participants, and upon any assignee or successor in
interest to the Company and upon the heirs, legal representatives and
beneficiaries of any Participant.

5.7   STATUS OF PARTICIPANTS.

      Stock Credits are not, and do not constitute, shares of Common Stock. No
right as a holder of shares of Common Stock shall devolve upon a Participant by
reason of his or her participation in the Program until such time as shares of
Common Stock are distributed in accordance with Article 3.


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5.8   STATEMENT OF ACCOUNT.

      After the end of each calendar quarter, each Participant in the Program
during the immediately preceding calendar quarter shall receive a statement of
his or her Stock Account under the Program as of the end of such preceding
calendar quarter. Such statement shall be in a form and contain such information
as is deemed appropriate by the Committee.

5.9   ENTIRE AGREEMENT.

      Each Participant shall agree to be bound by the terms of the Program as
set forth herein. This document contains the entire agreement of the Participant
and the Company with respect to the subject matter hereof. No modification or
claim of waiver of any of the provisions hereof shall be valid unless in writing
signed by the party against whom such modification or waiver is sought to be
enforced.

AGREED:                                   ACCEPTED:

PARTICIPANT                               ATMI, INC.


_____________________________             By: _________________________________
Date:
                                              Its:_____________________________

                                              Date:____________________________


Attachment:  Beneficiary Designation





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