To obtain a cryogenic refrigerating machine in which a filter can be easily replaced with another one in a short time.

A cryogenic refrigerating machine comprises tubular cylinders 1 and 2, tubular reciprocating displacers 3 and 4 in the cylinders 1 and 2, cold storage materials 5 and 6 with which the displacers 3 and 4 are filled, caps 13e, 13b, 13c and 13f respectively arranged at both the sides of the displacers 3 and 4 so as to hold the cold storage materials 5 and 6 in the displacers 3 and 4, and filters 11e, 11b, 11e and 11d respectively disposed between the caps 13e, 13b, 13c and 13f and the cold storage materials 5 and 6 to capture the abrasion powder of the cold storage materials 5 and 6 so that compressed gas is supplied to the cylinders 1 and 2 through the cold storage materials 5 and 6 and expanded to generate coldness. All the caps 13e, 13b, 13c and 13f are provided with pins 16, 17, 27 and 33 so that all the caps 13e, 13b, 13c and 13f are detachable.