<p>An air conditioner the maintenance of which can be easily carried out by improving the accessibility to an electric component is provided. The ceiling-mounted air conditioner (100) has a casing (4) containing an electric component box (70) which is a case (41) installed at an end on the upstream side of the casing (4) in the air flow direction. The case (41) contains an electric component (71) inside and has an openable/closable lid (43). Through a hinge (44), the electric component box (70) is rotated with respect to the casing (4). An inlet (4S) is formed by a part of the outer edge of the casing (4) and a part of the outer edge of the electric component box (70). The air conditioner can be switched between an operating mode in which the lid (43) of the electric component box (70) faces the lower surface and a maintenance mode in which the lid (43) faces the upstream side to narrow the area of the inlet (4S) in comparison with that in the operating mode by the rotation of the hinge (44).</p>
