A refrigeration apparatus is configured to perform a refrigeration cycle operation in which a high-pressure side attains a pressure that exceeds the critical pressure of a refrigerant used in the refrigeration cycle operation. The refrigeration apparatus includes a refrigerant circuit and a control unit. The refrigerant circuit has a plurality of constituent components including a compressor, a cooler, an expansion mechanism, and a heater. The control unit is operatively coupled to control at least one of the constituent components such that a quasi-subcooling degree is within a predetermined temperature range, the quasi-subcooling degree being a temperature difference between a quasi-condensation temperature and a cooler outlet refrigerant temperature, with the quasi-condensation temperature being the refrigerant temperature at which isobaric specific heat capacity of the refrigerant at the refrigerant pressure on the high-pressure side of the refrigeration cycle is at a maximum.