An air-conditioning apparatus for a vehicle having separate units for a driver's seat and an assistant driver's seat. Each of the units has first and second vent outlets opened to a cabin near the lateral side of the cabin and the center side of cabin. A sensor is provided for detecting an amount of the solar radiation. The sensor also can detect an azimuth angle and elevation angle of the sun with respect to the direction of movement. An increase in the thermal load due to the solar radiation is determined, and the calculated increase is allocated to the first and second vent outlets by changing the temperature and/or the amount of the air discharged from the respective outlets, so that the passenger can feel a uniform temperature irrespective of the position of the sun with respect to the direction of movement of the vehicle.