EXHIBIT 99.1

                    CERTIFICATION OF CHIEF EXECUTIVE OFFICER
                                   PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

As of the date  hereof,  I, Steven G.  Mihaylo,  certify,  pursuant to 18 U.S.C.
Section 1350, as adopted  pursuant to Section 906 of the  Sarbanes-Oxley  Act of
2002, that the Quarterly Report of Inter-Tel,  Incorporated on Form 10-Q for the
fiscal quarter ended September 30, 2002 fully complies with the  requirements of
Section  13(a)  or  15(d)  of the  Securities  exchange  Act of  1934  and  that
information  contained in such Quarterly  Report on Form 10-Q fairly presents in
all material  respects the  financial  condition  and results of  operations  of
Inter-Tel, Incorporated.


                                        By: /s/ Steven G. Mihaylo
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                                        Name: Steven G. Mihaylo
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                                        Title: Chief Executive Officer
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                                        Dated: November 8, 2002
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