PURPOSE: To achieve higher efficiency by setting a subcooler using a cooling water to be supplied to a supercooler from a heat storage tank as heat source between a condenser of a refrigerating machine and the supercooler to eliminate loss of heating value required for raising the temperature of the cooling water.

CONSTITUTION: Cooling water stored in an ice storage heat tank 21 is sent to an evaporator 1 as supercooler passing through a pump 22 for making ice and a ice trapping filter 24 and the water supercooled is returned to the ice storage heat tank 21 from a supercooling pipe 25 to produce sherbet-like ice. The ice is melted by return water of a load side device 26 being fed with a cooling water return pump 28 to be turned to cooling water, which is suppled to the load side device 26 with a supply pump 27. In this case, a subcooler 9 is provided in a refrigerant circuit between a condenser 5 and an orifice 8 to make the refrigerant flow in as leaving the condenser 5 to be turned to a liquid phase. The refrigerant is sucked with a refrigerant pump 6 to be scattered evenly among pipes 2 from a spray nozzle provided in the evaporator 1. This can reduce compression work thereby improving the efficiency of a refrigerating machine.