A vehicle air conditioner includes a control device and a heating refrigerant circuit having: a compressor that compresses and discharges a suctioned refrigerant; an internal condenser that releases heat of the discharged refrigerant; an expansion valve that reduces a pressure of the refrigerant which passes through the internal condenser and that expands the refrigerant; and an external heat exchanger that exchanges heat between the refrigerant which passes through the expansion valve and external air and that causes the refrigerant after the heat exchange to return to the compressor. The opening degree of the expansion valve is controlled by the control device to be increased at a start of a heating operation to more than an ordinary opening degree during a heating operation to start the compressor, and after a set time elapses, to be caused to return to the ordinary opening degree during a heating operation.