PURPOSE: To promote reliability by preventing the separation of a storing safety device of a stored object.

CONSTITUTION: An inside shape of a hard case 2 is wide enough to make it possible to move a CD case 1, and an opening section 27 capable of inserting the CD case is so formed that it is smaller than the CD case 1. A space bar of a lock mechanism is provided in a space made by insertion and approach of the CD case 1 and is locked. A side frame 22a having s space bar insertion port 28 of the hard case 2 is made to increase the thickness in comparison with the other side frame, and it is formed in the shape of a lense having a roughly semi-circular section to increase strength. A separation preventing projected slip prevention wall 50 is provided to the end of the rear 49 of the space bar at right angles to a space bar pushing surface 48 against which the CD case 1 of a space bar 42 is pushed. By the constitution, the separation of the CD case from a forced curve of the hard case can be prevented.