PURPOSE: To exactly prevent a malfunction so that a pickup stylus, etc. are not damaged carelessly, by controlling a pickup means by use of a disk-containing signal and a shutter opening and closing signal.

CONSTITUTION: A catch plate 43 is locked at its pushed-in position by a locking means 49, and also is detected by a detecting switch 53. Also, on a substrate 44, a pair of release pawls 50, 50 placed so as to relaese hooks by operating on levers 5, 5 of a caddy 2 are installed. Disk side detecting means 17 are installed in parallel with each other so as to face the passing surface of a disk pack guided by guide grooves 13, 13, and the detecting parts are slightly shifted to each other in the forward and backward direction and are placed. One switch 55 is installed to a place corresponding to a tapered surface 9 formed on the front end of the caddy 2, and the other switch 56 positioned in the rear is installed so as to come into press-contact with a flange 10 adjacent to the tapered surface 9.