EXHIBIT 31.2

CERTIFICATION PURSUANT TO RULE 13a-14(a) OR 15d-14(a) OF THE SECURITIES EXCHANGE ACT OF 1934, 
AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Walter A. Shephard, certify that:

|1) | I have reviewed this quarterly report on Form 10-Q of Zygo Corporation;                                                                                                                                                                                                                                                                                                                                                         
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|2) | Based on my knowledge, this 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 report;                                                                                                                      
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|3) | Based on my knowledge, the financial statements, and other financial information included in this 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 report;                                                                                                                                         
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|4) | The registrants other certifying officer(s) 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)) and internal control
over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:                                                                                         
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|   | 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 report is being prepared;                       
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|   | b)     Designed such internal control over financial
      reporting, or caused such internal control over financial reporting to
      be designed under our supervision, to provide reasonable assurance regarding
      the reliability of financial reporting and the preparation of financial
      statements for external purposes in accordance with generally accepted
    accounting principles;                      
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|   | c)     Evaluated the effectiveness of the registrants
      disclosure controls and procedures and presented in this report our conclusions
      about the effectiveness of the disclosure controls and procedures, as of
      the end of the period covered by this report based on such evaluation;
    and                                                                                                                
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|   | d)     Disclosed
      in this 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
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|5) | The registrants other certifying officer(s) 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 theregistrants board of directors (or persons performing the equivalent functions):                                                                                                                               
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|   | 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.                                                                                                                                                                                                                                     
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|Date: May 12, 2008 |  |                                       
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|                   |  | /s/ Walter A. Shephard                
|                   |  | Walter A. Shephard                    
|                   |  | Vice President, Finance,              
|                   |  | Chief Financial Officer, and Treasurer

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