Disclosed is an air conditioner. The air conditioner includes a tray in which humidifying water is stored by a predetermined height, the tray being detachably attached to a main body, a humidifying gear rotatably arranged in the tray so as to be detachably attached to the tray, a lifter provided at a periphery of the humidifying gear, the lifter being submerged under the humidifying water so as to scoop up the humidifying water during rotation of the humidifying gear, and a humidifying filter provided in the humidifying gear and spaced apart from the humidifying water such that the humidifying water is supplied from the lifter to the humidifying filter during rotation of the humidifying gear.