Cryogenic refrigerator

A cryogenic refrigerator, comprising:

• a compressor;
• an expansion space in which a high-pressure working gas discharged from a discharge side of the compressor is caused to expand;
• and
• a valve including
• a first member including a first channel connecting to the discharge side of the compressor;
• and
• a second member including a second channel connecting to the expansion space,
• wherein the first member and the second member are configured to rotate relative to and in contact with each other to connect or disconnect the first channel and the second channel,
• wherein, in a plane in which the first member and the second member are in contact, a first distance that is a distance of closest approach between the first channel and a valve circumference defined by a circumference of one of the first member and the second member having a smaller diameter is greater than a second distance that is a distance of closest approach between the second channel and the valve circumference.