In a vehicle air conditioner (1) employing an air-mix method, airflow which passed through a bypass channel (14) and airflow which passed through a heated air channel (13) are mixed in an air-mix area (15) located downstream of an air-mix damper (6) and the airflow is guided to a foot outlet (19) through a foot channel (18) provided on the back side of a partition wall (2A) constituting the heated air channel (13). The vehicle air conditioner includes a mixing enhancement portion (50) that makes airflow flowing along the partition wall (2A) flow toward the air-mix area (15) and an introduction portion (60) that is continuous with the mixing enhancement portion (50) and smoothly guides the airflow after air mixing to the foot channel (18) are provided at an end (30) of the partition wall (2A) constituting an outlet of the heated air channel (13).