A heat pump cycle includes a refrigerant circuit and a coolant circuit. A first heat exchanger and a second heat exchanger are disposed between the refrigerant circuit and the coolant circuit. The first heat exchanger includes an exterior heat exchanger that functions as an evaporator in a heating operation, and a radiator for radiating heat of a coolant. The second heat exchanger transmits a heat of high-pressure refrigerant to the coolant in the heating operation. A temperature of refrigerant within the second heat exchanger is higher than a temperature of refrigerant within the first heat exchanger. The heat obtained from the second heat exchanger is supplied to the first heat exchanger through the coolant. Further, the heat obtained from the second heat exchanger is stored in the coolant. In defrosting operation, the coolant that has stored the heat therein is supplied to the first heat exchanger.