In an air conditioner for a vehicle with an equipment controlled in accordance with a traveling state of the vehicle, a first heater is disposed to heat air to be blown into a vehicle compartment by using a coolant of the equipment as a heat source, and a second heater is adapted as an auxiliary heater to further heat the air heated by the first heater. A heating capacity of the first heater is controlled such that a temperature of the equipment is approached to a predetermined temperature when the thermal fluid after passing through the first heater returns the equipment, and a heating capacity of the second heater is controlled such that a temperature of air to be blown into the vehicle compartment becomes a desired temperature.