To provide a refrigerator capable of efficiently removing impurities in an operating gas without dropping refrigeration efficiency.

The refrigerator 1 which utilizes compression and expansion of an operating gas to generate a refrigerating operation includes: a casing 5 filled with the operating gas; a cylinder 7 which is provided inside the casing 5 and internally has a compression space N in which the operating gas is compressed; a piston 8 moving within the cylinder 7 in a predetermined axial line direction L; a piston support member 10 which is fixed to the cylinder 7 and freely moves the piston 8 in the axial line direction; and an adsorption member 20 which is disposed in a buffer space M that is any other space than the compression space N inside the casing 5 and adsorbs impurities in the operating gas. The piston support member 10 includes a first communication hole 16 communicating an outer buffer M1 outer than the piston support member 10 in the buffer space M and an inner buffer M2 inner than the piston support member 10 in the buffer space M.