PURPOSE: To electrically efficiently control input/output states of heat in response to an operating state when heat radiated from a compressor is input to a regenerator for storage and the heat stored in the regenerator is output to the compressor side.

CONSTITUTION: A regenerator 5 is arranged around a compressor 1 through a thermoelectric element 4 capable of electrically controlling a heat transfer state, heat radiated from the compressor 1 is input to the regenerator 5, heat input to and stored in the regenerator 5 is to be able to be output to the compressor 1 side through the element 4, and heat input/output states between the compressor 1 and the regenerator 5 is efficiently controlled by controlling the heat transfer function of the element 4 in response to the operating state of the compressor.