When an internal temperature of a freezing compartment becomes lower than a lower limit temperature during R-compartment F-compartment alternate cooling, starting R-individual overcool preventing control is requested. Then, the rotational speed of a compressor is decreased by one stage and, subsequently, a three-way valve enters “R-side open state”, and individual cooling of the refrigerating compartment is executed. Thereafter, every 30 seconds, the rotational speed of the compressor is decreased by one stage. When the refrigerating compartment becomes lower than a lower limit temperature, stopping R-individual overcool preventing control is requested. Then, the process shifts to individual cooling of the freezing compartment and then, after the freezing compartment to again become lower than the lower limit temperature, the compressor is stopped. When shifted to the individual cooling of the refrigerating compartment, the rotational speed of the compressor is drastically decreased in a short time.