PURPOSE: To restrain decrease of an open air suction quantity by appropriate construction of vent ports, and prevent degradation of comfortableness of passengers due to shortage of amount of ventilation, against action of running wind accompanying running of a vehicle.

CONSTITUTION: In an air conditioner for vehicle of which the indoor machine 3 constituted of a plurality of indoor heat exchangers 20, a plurality of indoor blowers 21, and the like is loaded under the floor of a vehicle, this air conditioner for vehicle is provided with a vent duct 22 which is provided with vent doors 23 to projectingly open from the sides of the vehicle to the outside of the vehicle and connected to the inlet parts of the indoor heat exchangers 20 on both sides of the indoor machine 3.