To enable unpolished rice to be stored under optimum conditions, by providing the control of a compressor and a fan with an unpolished rice mode to turn on a circulation fan synchronously with the ON of the compressor, and turn off it once while the compressor stops several times.

A controller has three modes for use in high humidity, low humidity, and for exclusive use for unpolished rice, in a stored program, and as occasion demands, the mode is set selectively Here, when the mode exclusively used for unpolished rice is set, a fan 17 for circulation is operated synchronously with the working of a compressor 11, and the circulation fan 17 is stopped, being delayed for a specified time from the stoppage of the compressor 11, and the humidity is kept at 60-70%. Therefore, the humidity within a storeroom can be kept between high humidity and low humidity. Moreover, in case that the storeroom is large, there is a fear of its getting tinged with low humidity, so the fan 11 for circulation is stopped, being delayed for a specified time only once while the compressor 11 stops several times. Hereby, the environment required for preservation of unpolished rice can be made.