A refrigerant heating performance is increased while suppressing an increase in weight or cost. A vehicle air-conditioning device (10) is provided with a heat pump cycle (16) for heating operation in which an electric compressor (50) for compressing refrigerant, a vehicle-cabin-interior condenser (26), a throttle (52), and a vehicle-cabin-exterior heat exchanger (54) are connected in that order via refrigerant piping. An inverter for the electric compressor (50) in which a power element comprising a highly heat-resistant semiconductor device is used is disposed on the electric compressor (50) so that the refrigerant compressed by the electric compressor (50) can be heated by the power element. During heating operation of the heat pump cycle (16), the refrigerant is heated by the power element.