A ceiling-mounted air conditioner is provided. The ceiling-mounted air conditioner includes a main body which is fixed onto a ceiling of a room where the ceiling-mounted air conditioner is installed and includes an air intake formed at the bottom thereof; a door panel which is connected to the bottom of the main body so as to be able to be attached to or detached from the main body and shuts or opens the air intake by being lifted up or down; a plurality of moving elements which are fixed onto the top surface of the door panel, are a predetermined distance apart from one another, and are lifted up or down so as to be able to lift up or down the door panel; and a plurality of rotation elements which are disposed at the main body so as to be able to rotate and thus to lift up or down the moving elements, wherein each of the moving elements includes a vertical portion having a cavity portion extending vertically therein and protruding vertically from the top surface of the door panel, a driving force transmitting portion formed on one side of the cavity portion and contacting a corresponding rotation element, and an elevation guide portion formed on the other side of the cavity portion and guiding the elevation of the vertical portion. Therefore, it is possible to improve the exterior appearance of the ceiling-mounted air conditioner.