A disc apparatus including: a disc tray on which a disc is mounted; an optical pickup unit which irradiates a light beam on the disc; a traverse assembly unit on which the optical pickup unit is mounted; a driving motor which is a power source for operating the disc tray, the optical pickup unit, and the traverse assembly unit; an inner circumference arrival sensor which detects whether the optical pickup unit arrives at the inner circumference of the disc; and an encoder sensor which detects the number of rotations of the driving motor when the driving motor rotates clockwise or counterclockwise, wherein based on the number of rotations of the driving motor in the clockwise direction, the optical pickup unit is moved to the inner circumference of the disc, and then the traverse assembly unit descends, so that the disc tray is opened.