To provide an inexpensive wall-buried air conditioner which can be operated not only in an indoor air-conditioning mode, but also in an outside air introducing mode and an exhaust mode, and has a simple structure.

A wall-buried air conditioner is provided with a fan 3 which is set up in the central section of the main body 2 of an indoor machine buried in a wall 1 dividing the inside R of a room from the outside U, an indoor air sucking flow passage 4 which introduces the air in the room to the suction side of the fan 3, an indoor air suction damper 14 which opens/closes the flow passage 4, an outdoor air sucking flow passage 5 which introduces the outdoor air to the suction side of the fan 3, and an outdoor air suction damper 15 which opens/closes the passage 5 are provided. The air conditioner is driven in such a state that blowing-out air switching dampers 16 and 17 which lead the air blown out from the fan 3 and passed through heat exchangers 8 and 9 to the inside R of the room or outside U by switching the indoor blowing-out flow passages 10 and 11 and outdoor blowing-out flow passages 12 and 13 are linked to the indoor and outdoor air suction dampers 14 and 15. Therefore, the air- conditioner can be driven in a plurality of modes of an indoor air-conditioning mode, an outside air introducing mode, an exhaust mode, etc.