To provide a Stirling engine which can conform to future regulations of HCFC and HFC based refrigerants and can enhance cooling efficiency through utilization of latent heat.

The Stirling refrigeration system comprises a Stirling refrigerating machine 1 having a low temperature section 3 cooled down to a cryogenic temperature, and a cooling compartment 10 wherein a refrigerant circulation circuit is formed by sequentially coupling a condenser 5 disposed contiguously to the low temperature section 3, an evaporator 7 disposed in the cooling compartment 10, and a circulation pump 6 through refrigerant piping 8. When refrigerant is circulated through the refrigerant circulation circuit, cold heat received by the refrigerant as latent heat through the condenser 5 is carried to the evaporator 7 and the cooling compartment 10 is cooled utilizing the heat of evaporation of the refrigerant. Carbon dioxide existing in the natural world can be employed suitably as the refrigerant. Since it is inexpensive and harmless to the environment and the human body, future regulations of HCFC and HFC based refrigerants can be conformed sufficiently.