A disc device has a sliding member 16 that operates in response to a rotational force of the first partially toothless gear 13 to disconnect a power transmission system from a disc conveying roller, and a protruding portion 16a disposed on this sliding member 16 is brought into contact with a rising portion 17b of a rotary lever 17 at an initial position of the sliding member before the sliding member starts operating, so as to restrict a rotation of the rotary lever 17 in such a way that a pin 17a does not come into contact with a wall surface of a cam groove 13d.