An air conditioner principally includes a casing having a casing lower part formed by an alternating sequence of four panel side parts and four corner parts. The casing further has main outlets disposed along each of the panel side parts, and auxiliary outlets disposed at the corner parts. The air conditioner further includes horizontal flaps rotatably supported about longitudinal axes of the main outlets. A circumferential edge part of each of the auxiliary outlets is formed so that the air from each of the auxiliary outlets is blown out in a fixed direction.