A ceiling-mounted air-conditioning indoor unit which is convenient to use because dust collected by filter cleaning operation can be easily discarded. In the air-conditioning indoor unit (2), a suction opening (20a) is formed in the lower surface of a body (20). When operation of the indoor unit is stopped, a movable panel (24) closes the suction opening (20a), and when maintenance of the indoor unit is performed, the movable panel (24) descends to a predetermined position. A lifting-lowering device (7) moves the movable panel (24) upward and downward. A filter (9) removes dust contained in air flowing inward from the suction opening (20a). A roller (102) moves the filter (9) when the filter (9) is cleaned. A brush (108) removes dust adhering to the filter (9). A brush-driving motor (108f) operates the brush (108). A dust box (109) is removably mounted to the movable panel (24) and contains dust removed from the filter (9).