<PAGE>

                                                                    EXHIBIT 31.1



                    CERTIFICATION OF CHIEF EXECUTIVE OFFICER
      AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002
                            RULE 13a-14(a)/15d-14(a)

I, Glenn H. Epstein, certify that:

       1.    I have reviewed this annual report on Form 10-K of Intermagnetics
             General Corp. ("the Registrant");

       2.    Based on my knowledge, this annual 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 annual report;

       3.    Based on my knowledge, the financial statements, and other
             financial information included in this annual 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 annual 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)) and internal
             control over financial reporting (as defined in Exchange Act Rules
             13a-15(f)) 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 annual report is being
                 prepared;

             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;

             c.  evaluated the effectiveness of the Registrant's disclosure
                 controls and procedures and presented in this annual report our
                 conclusions about the effectiveness of the disclosure controls
                 and procedures, as of the end of the period covered by this
                 annual report based on such evaluation; and

             d.  disclosed in this annual 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:

             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.

Dated: August 12, 2005

                          /s/Glenn H. Epstein
                          ----------------------------------------
                          Glenn H. Epstein
                          Chairman and Chief Executive Officer