PURPOSE: To rapidly cope even if a room temperature is abruptly altered by preferentially supplying the refrigerant of a refrigerating cycle to an evaporator for the freezing operation of a cold storage agent when the room temperature is a predetermined value or higher, thermally exchanging the air in the room by the evaporator, and diffusing cold air into the room.

CONSTITUTION: An indoor temperature detecting thermostat switch 16 is provided in the room of a case 2 as indoor temperature detecting means, and the switch 16 is switched at 0°C. If the temperature in the case chamber is 0°C or higher, the indoor temperature thermostat switch 16 is shifted to a contact 33a, a cooling motor 32 is energized, a cooling fan 14 is driven, a relay coil 31 is also energized, a relay contactor 22 is closed to drive a compressor motor 23 and a condenser motor 24. As a result, since a solenoid three-way valve 18 is not energized, the refrigerant of a freezing cycle is fed to a quick cooling evaporator 12, and cold air is diffused into the chamber by the drive of the cooling fan 14, thereby abruptly cooling in the case 2.