To provide an optical disc device in which an identification and a disc ejection control processing for an optical disc with a high transmitting property and an 8-cm optical disc attached to an adapter can be effected easily and positively. There are provided a body capable of receiving an optical disc therein, an insertion/ejection port capable of insertion and ejection of the optical disc relative to the interior of the body, and rollers which are provided within the body, and rotate, while holding the optical disc therebetween, so as to convey the optical disc into the interior of the body. A mechanical detector, having a contact element for contact with at least one of obverse and reverse surfaces of the optical disc to detect the optical disc, is provided within the body so that an identification and a disc ejection control processing for optical discs can be effected easily and positively.