To provide the cooling/heating medium liquid, a method and a device for heating/cooling the thermal storage medium and the cool storage medium possible to heat and cool the thermal storage medium and the cool storage medium for a long time at a constant temperature specified to show and keep the effect in the case of heating/cooling the thermal storage medium and the cool storage medium with a means for heating/cooling the heating medium/cooling medium or the thermal storage medium/cool storage medium manufactured by using a technology possible to keep a desirably set constant temperature, and to provide a container for the same, and usage thereof.

A heating/cooling unit device formed of a water-proof module members capable of heating/cooling at a desirably set constant temperature is used. The module member is inserted into the thermal storage/cool storage medium container and installed for unifying, or the module member is fitted to a container member body freely to be removed to form a device freely to be located. The thermal storage medium/cool storage medium having an additional work for heating/cooling at a desirably set constant temperature is arranged in a heat insulating case for use.