Radiometric calibration with the Moon (called the lunar calibration) is a promising method for evaluating the performance of instruments onboard satellites orbiting around the Earth. In particular, the lunar calibration can provide inflight radiometric calibration opportunities for nano/microsatellites whose priorities are technical demonstrations and scientific observations during rather a short lifetime. In this study, we have applied the lunar calibration to a recently launched microsatellite named RISESAT. RISESAT had observed the Moon every month for a half year after the launch with an onboard instrument OOC. By simulating the Moon brightness for each observation based on the ROLO and SELENE/SP Moon models, we succeeded to measure < 2 % of a small degradation in four months. Further comparison of the observation and the simulation irradiance of the Moon revealed the bluing trend in the OOC's inter-band ratio.