A vehicle air-conditioning apparatus includes a refrigerant circuit and a control unit which controls the refrigerant circuit, and is mounted on a vehicle. The control unit determines whether or not the vehicle is stationary based on position information or speed information on the vehicle, causes the refrigerant circuit to operate when the vehicle is stationary, acquires state data on the refrigerant circuit at the time when the vehicle is stationary, and detects whether abnormality occurs in the refrigerant circuit based on the state data.