Osaka Gas and Tokyo Gas have developed 25kW class SOFC cogeneration system jointly with Westinghouse Electric Corporation. This is the first SOFC cogeneration system in the world, which includes a DC to AC power conditioner and a Heat recovery steam generator. The system is able to provide 33kW net AC power and 27kW steam at 8kg/cm2 gauge pressure at peak operation. After approx. 700 hours initial operation at the manufacturing facility of Westinghouse, the system was introduced at a test site in Osaka Gas. Verification test was started in the middle of October 1992. Based on the test results, SOFC technology and its potential for cogeneration will be evaluated.