A refrigerant circuit (5) of an air conditioner (1) performs single-stage compression refrigeration cycle. In the refrigerant circuit (5), a second heat exchanger (40) is provided downstream of a first heat exchanger (30). The first heat exchanger (30) cools a high-pressure refrigerant in a high-pressure flow path (31) by causing the high-pressure refrigerant to exchange heat with a first intermediate-pressure refrigerant in an intermediate-pressure flow path (32). A first intermediate-pressure gas refrigerant generated by the first heat exchanger (30) is supplied to a first compression mechanism (71). A second intermediate-pressure refrigerant having a lower pressure than the first intermediate-pressure refrigerant is supplied to an intermediate-pressure flow path (42) of the second heat exchanger (40). The second heat exchanger (40) further cools the high-pressure refrigerant in a high-pressure flow path (41) by causing the high-pressure refrigerant to exchange heat with the second intermediate-pressure refrigerant in the intermediate-pressure flow path (42). A second intermediate-pressure gas refrigerant generated by the second heat exchanger (40) is supplied to a second compression mechanism (72).
