To improve a coefficient of performance (COP) and therefore a refrigerating capacity in the refrigerating cycle using carbon dioxide as a refrigerant and using an expanding machine and an aspirator.

A first gas-liquid separator 15 is disposed between the expanding machine 14 and the aspirator 20, a gas outlet side of the first gas separator and a suction side of a second compressor 12 are connected by piping, a liquid outlet side of the first gas-liquid separator is connected with the aspirator by piping, a second gas-liquid separator 16 is disposed between the aspirator and a first compressor 10, a gas outlet side of the second gas-liquid separator and a suction side of the first compressor are connected by piping, on the other hand, a liquid outlet side of the second gas-liquid separator is connected to an evaporator 18 by piping through a throttle device 17, an outlet of the evaporator is connected to a suction port 22 of the aspirator by piping, and internal heat exchangers 30 exchanging heat to each other, are disposed in the piping between a liquid outlet side of the first gas-liquid separator 15 and the aspirator 20, and the piping between an outlet of the evaporator 18 and the suction port 22 of the aspirator.