PURPOSE: To obtain a packaged rice cake capable of retaining the quality for a long period, by packaging a rice cake in a packaging material transmitting ultraviolet light, and irradiating the above-mentioned packaged rice cake with ultraviolet light to a sterilize the surface of the rice cake and inner and outer surfaces of the packaging material.

CONSTITUTION: A molded rice cake is packaged in a packaging material transmitting ultraviolet light, preferably film or container such as polyethylene, and the resultant packaged rice cake is then irradiated with ultraviolet light to sterilize the surface of the rice cake and inner and outer surfaces of the packaging material. The irradiation of the ultraviolet light may be carried out for ex ampler for 2W5sec in the case of the ultraviolet light at 100mW/cm2 illuminance.