PURPOSE: To efficiently return oil to a compressor by separating oil in refrigerant gas discharged from the compressor in a refrigerator.

CONSTITUTION: In a refrigerator, a condenser 2 is formed of a first condenser 21 and a second condenser 22 having a larger capacity than that of the condenser 21. The condenser 21 is connected to a discharge side of a compressor 1, and the condenser 22 is connected to a pressure reducing unit 3. On the other hand, a gas/liquid separator 5 is interposed between an output side of the condenser 21 and an inlet side of the condenser 22, and a bottom of the separator 5 is connected to a suction side of the compressor 1 through pressure reducing means 6 and heating means 7. Thus, oil discharged from the compressor 1 is dissolved in the condensed liquid of the condenser 21. Further, the condensed liquid is reduced under pressure, heated to vaporize refrigerant in the condensed liquid, and returned to a suction side of the compressor 1 together with the oil.