To provide a constant temperature control system for cooling and humidifying, heating and humidifying and dehumidifying a storage chamber.

A chilled water tank 7 and a warm water tank 20 are provided out of a storage chamber 100, and warm water in the tank 20 is supplied to an air washer 5 in the chamber 100. Thus, the warm water is sprayed from a shower 2 to heat and humidify in the chamber 100. And, a cooling coil 31 is provided in the washer 5 to supply chilled water from the tank 7. Thus, the chamber 100 is dehumidified.