To provide a cryogenic refrigerator which achieves the downsizing and the weight reduction while improving the thermal efficiency of a refrigerant gas line and a stage.

A cryogenic refrigerator includes: a JT circuit 20 including a JT compressor 21 which compresses a refrigerant gas, a JT valve 24 which adiabatically expands the high pressure refrigerant gas supplied from the JT compressor 21 and generates cold, a stage 40A which is cooled by the refrigerant gas cooled by the generated cold, and a high pressure side refrigerant gas line 22 and a low pressure side refrigerant gas line 23 which connect the JT compressor 21, the JT valve 24, and the stage 40A; and a GM refrigerating machine 11 which pre-cools the refrigerant gas flowing in the high pressure side refrigerant gas line 22. A refrigerant gas passage 42A, in which the refrigerant gas flows, is provided in a stage body 41A of the stage 40A, and heat exchange is conducted between the refrigerant gas flowing in the refrigerant gas passage 42A and the stage body 41A.