SUPPLEMENTAL BENEFIT PLAN
                                       OF
                          HELIX TECHNOLOGY CORPORATION

                             Effective April 1, 1999


         Section 1. Purpose.  This Supplemental Benefit Plan of Helix Technology
Corporation  (the  "Supplemental  Benefit  Plan")  provides  for the  payment of
additional  compensation to certain  employees of Helix  Technology  Corporation
(the  "Company") to  compensate  them for benefits not payable to them under the
Helix Technology Corporation Employees' Pension Plan (the "Pension Plan") due to
limits on Pension Plan  benefits  imposed by the  Internal  Revenue Code of 1986
(the "Code").

         Section 2.  Eligibility.  A person is eligible for benefits  under this
Supplemental  Benefit  Plan if the person is an employee of the Company who is a
participant  in the Pension Plan and who has been  designated  by the  Company's
Board  of  Directors  as a  participant  in this  Supplemental  Benefit  Plan (a
"Participant").

         Section 3. Supplemental  Benefit.  The benefit payable to a Participant
under this Supplemental Benefit Plan (the "Supplemental  Benefit") is the excess
of (a) the  benefit  that would be payable to the  Participant  from the Pension
Plan if the benefit under the Pension Plan were calculated without regard to the
limitation  on the amount of the benefit  imposed by section  415(b) of the Code
and the limitation on the amount of compensation  that may be taken into account
in calculating  the benefit  imposed by section  401(a)(17) of the Code over (b)
the benefit  actually  payable from the Pension Plan. The  Supplemental  Benefit
will be determined on a single life annuity basis.  Actuarial  equivalence under
this Plan, including  conversions to other permitted forms of benefits,  will be
based on the actuarial  assumptions  in the Pension Plan at the time the benefit
begins to be paid from the Pension Plan.

         Section 4. Time and Manner of Payment.  Subject to the other provisions
of this Plan, the Company will pay the  Supplemental  Benefit to the Participant
at the same  time or times  and in the same  form or forms as the  Participant's
benefit is paid from the Pension  Plan.  All forms of benefit  payable under the
Supplemental Benefit Plan will be actuarilly equivalent.

         Section 5.  Death.  If the  Participant  dies  before his or her entire
benefit has been paid from this Supplemental Benefit Plan, any unpaid portion of
the  Supplemental  Benefit will be paid to the same extent,  at the same time or
times, in the same form or forms,  and to the same  beneficiary or beneficiaries
as a death benefit is paid to the  Participant's  beneficiary  or  beneficiaries
under the Pension Plan.

         Section 6. Company's Right to Change Time or Manner of Payment.  In the
best interest of the financial  integrity and administration of the Supplemental
Benefit Plan,  the Company may, at any time at or after  occurrence of the event
that causes a Participant's
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Supplemental  Benefit to begin to be paid,  shorten  the  period  over which the
Supplemental  Benefit will be paid or change the form in which the  Supplemental
Benefit  will be paid,  provided  that the  changed  period or form  produces  a
benefit that is actuarially  equivalent to the  Supplemental  Benefit payable at
the time and in the form that the  Participant's  benefit  is  payable  from the
Pension Plan.

         Section 7. Unfunded  Obligation;  Trust. The obligations of the Company
to make payments  under this Plan will be unfunded,  except that the Company may
in its discretion arrange for a trust to hold assets that may be used to satisfy
the Company's  obligations under the Plan, but only if the establishment of such
a trust will not cause  Participants  to have any rights  under this Plan or the
trust  greater  than the rights of general  unsecured  creditors of the company.
Participants may not assign their rights under this Plan.

         Section  8.  Separable  Plan.  To the  extent  that this Plan  provides
benefits in excess of the limit of section 415 of the Code, those benefits shall
be a separable part of the Plan; and that separable part will be a separate plan
that is an excess  benefit  plan  within the  meaning  of  section  3(36) of the
Employee Retirement Income Security Act of 1974, as amended.

         Section 9.  Administration.  This  Plan  will  be  administered  by the
Human  Resources  and  Compensation  Committee  of the Board of  Directors  (the
"Administrator"). The Administrator is the named fiduciary of the Plan.

         Section  10.  Effective  Date;  Amendment;  Termination.  This  Plan is
effective  for  benefits  paid on or  after  April  1,  1999.  the  Plan  may be
terminated or amended in any respect by the Administrator, provided that no such
termination  or amendment may reduce the benefit  payable to a Participant  with
respect to the benefit earned before the date of such  termination or amendment.
The Company's obligations under this Plan shall be binding upon any successor to
substantially all the assets and business of the Company.

         Section 11.  Governing Law.  To the extent not governed by federal law,
this Plan will be construed,  enforced,  and administered in accordance with the
laws of the Commonwealth of Massachusetts.

         By signing this document,  a duly authorized officer of the Company has
acknowledged adoption of this Plan by the Company.

                                                   HELIX TECHNOLOGY CORPORATION


                                                   By    /s/Michael El-Hillow
                                                         ---------------------
                                                         Michael El-Hillow
                                                         Senior Vice President