To enhance an overall efficiency.

A cold side device is provided with a cold storage side compressor 3, a condenser 4, a liquid receiver 22, a cold storage side evaporator 13 and a cold storage side evaporator 28. A freezing side device is provided with a freezing side compressor 2, a condenser 29 and a freezing side evaporator 19. A cascade condenser 24 heat-exchanges an evaporated refrigerant by the cold storage side evaporator 28 with a refrigerant gas flowing to the freezing side condenser 29 by unifying the cold storage side evaporator 28 with the freezing side evaporator 29 and condenses the refrigerant gas, thereby dropping the condensation temperature and increasing the degree of supercooling so that the overall efficiency may be enhanced.