Abstract: A cooling and heating device having a cooling cycle circuit and a heating cycle circuit with a refrigerant heater for heating refrigerant includes a cooling circuit extending from a compressor through an outdoor heat exchanger, a resistance element (capillary) and an indoor heat exchanger to the suction inlet side of the compressor; and a heating circuit extending from between the discharge outlet side of the compressor and the outdoor heat exchanger directly through the indoor heat exchanger and the refrigerant heater to the suction inlet side of the compressor. In the heating operation, the high temperature refrigerant from the compressor, which is heated by the refrigerant heater, flows in the indoor heat exchanger in a direction opposite to that in which the refrigerant flows in the cooling operation, so that the refrigerant radiates heat through the indoor heat exchanger, and the refrigerant phases on either side of the indoor heat exchanger are the same for either cooling or heating.