To realize an air conditioner for a vehicle capable of preventing flow-out of the conditioned air, which is blown from an air conditioner unit, out of a cabin when opening a door.

An air curtain unit 30 is provided to blow the air for forming an air curtain opposite to a door opening part. An air conditioning control device 20 drives the air curtain unit 20 when the door in the opening condition is detected, and operates the air conditioner unit 10 by forcibly selecting the inside air mode operating condition. With this structure, flow-out of the conditioned air, which is blown from the air conditioner unit, out of the cabin can be prevented.