A refrigeration apparatus comprising: a water tube system having a water inlet tube for leading water supplied from the exterior to a water branching point, first branching water tubes (904, 905) and second branching water tubes (902, 903) extending from the water branching point, and a water outlet tube leading out to the exterior from a convergent point where the first branching water tubes (904, 905) and the second branching water tubes (902, 903) converge, wherein active refrigerant is in a supercritical state in at least part of the refrigeration cycle; a main expansion mechanism for depressurizing the refrigerant; an evaporator which is connected with the main expansion mechanism and which evaporates refrigerant; a first compression element for drawing in refrigerant that has passed through the evaporator and for compressing and discharging the refrigerant; a second compression element for drawing in the refrigerant discharged from the first compression element and for compressing and discharging the refrigerant; a first refrigerant tube for drawing the refrigerant discharged from the first compression element into the second compression element; a first heat exchanger for performing heat exchange between the refrigerant passing through the first refrigerant tube and the water flowing through the first branching water tubes (904, 905); second refrigerant tubes (71, 72) connecting a discharge side of the second compression element to one end of a second heat exchanger and the other end of the second heat exchanger to the main expansion mechanism; so that, during operation, the second heat exchanger subjects the refrigerant passing through the second refrigerant tubes (71, 72) to heat exchange with the water flowing through the second branching water tubes (902, 903), and not to heat exchange with the water flowing through the water inlet tube, whereby said water flowing through the first branching water tubes (904, 905) is not being heated by heat exchange with the refrigerant before flowing into the first heat exchanger and said water flowing through the second branching water tubes (902, 903) is not being heated by heat exchange with the refrigerant before flowing into the second heat exchanger a water tube system having a water inlet tube for leading water supplied from the exterior to a water branching point, first branching water tubes (904, 905) and second branching water tubes (902, 903) extending from the water branching point, and a water outlet tube leading out to the exterior from a convergent point where the first branching water tubes (904, 905) and the second branching water tubes (902, 903) converge, wherein active refrigerant is in a supercritical state in at least part of the refrigeration cycle; a main expansion mechanism for depressurizing the refrigerant; an evaporator which is connected with the main expansion mechanism and which evaporates refrigerant; a first compression element for drawing in refrigerant that has passed through the evaporator and for compressing and discharging the refrigerant; a second compression element for drawing in the refrigerant discharged from the first compression element and for compressing and discharging the refrigerant; a first refrigerant tube for drawing the refrigerant discharged from the first compression element into the second compression element; a first heat exchanger for performing heat exchange between the refrigerant passing through the first refrigerant tube and the water flowing through the first branching water tubes (904, 905); second refrigerant tubes (71, 72) connecting a discharge side of the second compression element to one end of a second heat exchanger and the other end of the second heat exchanger to the main expansion mechanism; so that, during operation, the second heat exchanger subjects the refrigerant passing through the second refrigerant tubes (71, 72) to heat exchange with the water flowing through the second branching water tubes (902, 903), and not to heat exchange with the water flowing through the water inlet tube, whereby said water flowing through the first branching water tubes (904, 905) is not being heated by heat exchange with the refrigerant before flowing into the first heat exchanger and said water flowing through the second branching water tubes (902, 903) is not being heated by heat exchange with the refrigerant before flowing into the second heat exchanger