To provide a cooling system enabling execution of cooling by a plurality of kinds of coolers and also being simple, small-sized and excellent in economics and safety.

A brine supply tank 2a is connected to the discharge side of a brine chiller unit 1 through a piping, while a brine recovery tank 2b is connected to the inflow side through a piping provided with a brine pump 6. The brine supply tank 2a is connected to the inflow side of a brine cooler 5a through a piping provided with a brine pump 7 and a motor operated valve 8 for temperature regulation, while the brine recovery tank 2b is connected to the discharge side through a piping. The brine supply tank 2a is connected to the brine inflow side of an ice storage tank 3 through a piping branched from the brine pump 7 and provided with a flow regulating valve 9 and a motor operated opening- closing valve 10, while the brine recovery tank 2b is connected to the brine discharge side through a piping. The chilled water discharge side of the ice storage tank 3 is connected to the inflow side of a chilled water cooler 4a through a piping provided with a chilled water pump 11, while the chilled water inflow side of the tank 3 is connected to the discharge side through a piping.