Abstract: A cooling device for a plurality of coolant circuits for equipment to be cooled, also those having greatly differing cooling power requirements, whose evaporator is disposed in a refrigerant circuit including a compressor, a condenser and an expansion valve. A thermostat switches on the compressor, dependent on the temperature of the coolant in the cooling circuits as measured upstream of the evaporator, if the switching temperature of the coolant is reached and switches off the compressor if the switching temperature is no longer reached.