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 September 30, 2002, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Robert M. Ringstad, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 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/ Robert M. Ringstad

Print Name: Robert M. Ringstad

Print Title: Chief Financial Officer