Exhibit 99.2 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report of APA Optics, Inc. (the "Company") on Form 10-Q for the period ending December 31, 2002, as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, David R. Peters, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Sec. 1350, as adopted pursuant to Sec. 906 of the Sarbanes-Oxley Act of 2002, that: 1. The Report fully complies with the requirements of Sections 13(a) or 15(d) of the Securities Exchange Act of 1934; and 2. The information contained in the Report fairly represents, in all material respects, the financial condition and results of operations of the Company. Signature: /s/ David R. Peters ------------------- Print Name: David R. Peters --------------- Print Title: Chief Financial Officer -----------------------