A cooling system includes an evaporator for evaporating a refrigerant to cool an object to be cooled; a refrigerant-supply-flow-rate regulator for regulating a flow rate of the refrigerant to be supplied to the evaporator; a condenser for condensing the refrigerant by cooling the refrigerant by use of a chilled fluid; and a chilled-fluid-flow-rate regulator for regulating a flow rate of the chilled fluid to be supplied to the condenser, the refrigerant condensed by the condenser being to be pressurized to be supplied to the evaporator. The chilled-fluid-flow-rate regulator regulates a flow rate of the fluid, to be supplied to the evaporator, for a temperature of the refrigerant condensed to come to a predetermined target refrigerant-liquid temperature, and the refrigerant-supply-flow-rate regulator regulates a flow rate of the refrigerant, to be supplied to the evaporator, for a temperature of the object cooled to come to a predetermined target cooling temperature.