a disc player is disclosed which includes a casing having a disc inserting opening , a turntable driven by a spindle motor , a clamper arm operating means for operating a clamper arm in cooperation with said turntable , a centering mechanism for guiding a disc from the disc inserting opening onto the turntable , the centering mechanism including a pair of centering arms each having at distal end portions contact portions which are to be brought into contact with a circumferential edge of the disc , the centering arms being pivotally movable at a predetermined distance in the disc inserting opening , a detecting lever for detecting a condition that the disc is laid on the turntable , and a disc double insertion preventing lock linkage for preventing another disc from being inserted into the casing through the disc inserting opening when the first - mentioned disc is already located on the turntable , the double insertion preventing lock linkage being in cooperation with the centering mechanism .