EXHIBIT 31.2

CERTIFICATION OF DISCLOSUREIN THE REGISTRANTS QUARTERLY REPORT

I, Walter A. Shephard, certify that:

1.  
          I have reviewed this quarterly report on Form 10-Q of Zygo Corporation;

2.  
          Based on my knowledge, this quarterly report does not contain any untrue
          statement of a material fact or omit to state a material fact necessary to make
          the statements made, in light of the circumstances under which such statements
          were made, not misleading with respect to the period covered by this quarterly
          report;

3.  
          Based on my knowledge, the financial statements, and other financial information
          included in this quarterly report, fairly present in all material respects the
          financial condition, results of operations and cash flows of the registrant as
          of, and for, the periods presented in this quarterly report.

4.  
          The registrants other certifying officer and I are responsible for
          establishing and maintaining disclosure controls and procedures (as defined in
          Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant and have:

(a)  designed such disclosure controls and procedures, or caused such disclosure
          controls and procedures to be designed under our supervision, to ensure that
          material information relating to the registrant, including its consolidated
          subsidiaries, is made known to us by others within those entities, particularly
          during the period in which this quarterly report is being prepared;

(b)  evaluated the effectiveness of the registrants disclosure controls and
          procedures and presented in this quarterly report our conclusions about the
          effectiveness of the disclosure controls and procedures, as of the end of the
          period covered by this quarterly report based on such evaluation; and

(c)  disclosed in this quarterly report any change in the registrants internal
          control over financial reporting that occurred during the registrants
most recent fiscal quarter (the registrants fourth fiscal quarter in the
case of an annual report) that has materially affected, or is reasonably likely
to  materially affect, the registrants internal control over financial
          reporting; and

5.    
          The registrants other certifying officer and I have disclosed, based on
          our most recent evaluation of internal control over financial reporting, to the
          registrants auditors and the audit committee of the registrants
          board of directors (or persons performing the equivalent functions):

(a)  all significant deficiencies and material weaknesses in the design or operation
          of internal control over financial reporting which are reasonably likely to
          adversely affect the registrants ability to record, process, summarize
and           report financial information; and

(b)  any fraud, whether or not material, that involves management or other employees
          who have a significant role in the registrants internal control over
          financial reporting.

Date: May 6, 2005

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| |  | /s/ Walter A. ShephardWalter A. Shephard
Vice President, Finance
Chief Financial Officer