A number of studies on airborne pollutants and microorganisms using ultraviolet sterilization have been conducted. Countermeasures are also needed to be taken against contamination and damage that occur on indoor surfaces in addition to indoor air. In this study, a method to predict UV-C intensity distribution using radiance calculation was introduced for the purpose of surface sterilization using UVGI systems and compared with the measured UVC intensities in a kitchen model room. The results of calculations showed a similar distribution of ultraviolet intensity with the measured intensities, although there was some discrepancy, probably due to different reflectance of building materials. And some bacteria and viruses occasionally identified in kitchens were predicted to be sterilized 99.9% only after about 30 minutes of UV-C irradiation with the figure 90% for fungi. The sterilization performance of UVGI and exposure time to UV-C were reasonably predicted using the radiance calculation method, and UV sterilization can be achieved with great effect even after a short period of time.