PURPOSE: To obtain a disk reproducing device which makes an opening/closing door close even at the time of setting a disk cartridge.

CONSTITUTION: A hinge is provided at the lower part of the opening/closing door 16 provided on an opening 18 of a casing to enable opening and closing the upper end side of the opening/closing door 16, simultaneously to energize the opening/closing door 16 in the closing direction by a energizing means 23, and an opening piece 17 which forwardly extends is provided at the upper end of the opening/closing door 16, and the opening/closing door 16 is opened by hanging the tip of the disk cartridge onto the opening piece 17 to insert the disk cartridge into a cartridge shell as it is. Further, a slit 26a in the hinge of the opening/closing door 16 is left open in the direction orthogonally intersecting with the opening/closing door 16. Further, the opening/closing door 16 may be so provided as to be turned upside down, too.