PURPOSE: To prevent sound jump due to stagnation of air vibration in a storage space without inducing deterioration of appearance and reduction in strength by laying out a hole for relieving air vibration formed by a blind lattice so that it is shaped in a specified design.

CONSTITUTION: A plurality of air vibration relief holes 21 which are constituted by a blind lattice 20 are formed at both sides of a transparent panel 8 of a disk lid 7. The blind lattice 20 falls in one piece with the section being in L shape from the main body of the disk lid 7. No air vibration relief hole 21 can be seen directly when viewed from the upper part and can be seen at all from the front, which is quite natural. A plurality of air vibration relief holes 21 at the left and right indicate a design where stripes are aligned in parallel when viewed from the top, thus preventing appearance from deteriorating. Also, the blind lattice 20 is in a large structure with a sectional secondary moment, thus preventing strength from deteriorating.