A computing device calculates a quality of a refrigerant flowing out of an expansion device on the basis of an inlet liquid enthalpy calculated on the basis of a temperature of the refrigerant flowing into the expansion device, and a saturated gas enthalpy and a saturated liquid enthalpy calculated on the basis of a temperature or pressure of the refrigerant flowing out of the expansion device; calculates a liquid-phase concentration and a gas-phase concentration of the refrigerant flowing out of the expansion device on the basis of the temperature and pressure of the refrigerant flowing out of the expansion device; and calculates a composition of the refrigerant circulating in a refrigeration cycle on the basis of the calculated quality, liquid-phase concentration, and gas-phase concentration.