To provide an air conditioner having a high energy efficiency by installing a flow-rate adjustment member.

The vehicle air conditioner 1 installed on a vehicle ceiling 11 includes a cold source 4 for transferring heat from one surface to the other surface; and an outside air duct 5 for forming a ventilation passage in the vehicle ceiling 11. The outside air duct 5 includes a first outside air inlet section 5a1 provided with a first outside air inlet port 5a2 for admitting air by using a wind pressure during traveling of a vehicle 10; a second outside air inlet section 5a3 provided with a second outside air inlet port 5a4 and an outside air fan 6, and admitting outside air from the second outside air inlet port 5a4 by the outside air fan 6; an outside air heat transfer section 5c communicated to the first outside air inlet section 5a1 and the second outside air inlet section 5a3, and exposing one surface of the cold source 4; and an outside air delivery section 5b communicated to the outside air heat transfer section 5c and provided with an outside air delivery port 5b1. The flow-rate adjustment member 9 for preventing air from flowing from the outside air heat transfer section 5c to the first outside air inlet section 5a1 is installed between the first outside air inlet section 5a1 and the outside air heat transfer section 5c.