PURPOSE: To improve the strength of an opening edge on the cover plate side without increasing the thickness of a cover plate and to enable maintenance of a distance between the top plate and a bottom plate of an opening even at the intermediate part of the opening by a method wherein an erection is erected to the edge on the cover plate side of the opening the one side part of which is covered with the cover plate.

CONSTITUTION: Rails 3 and 4 are annularly mounted to the under surface of a top plate 1 additionally serving as the bottom plate of a ceiling closet 12 with sliding doors and a bottom plate 2, respectively, of a containing device. A tubular frame 6 to hold a net-cage-like containing body 5 is formed approximately in square-shape as seen from a front. A plurality of the frames 6... are intercoupled at upper and lower parts by means of coupling bodies 13, and are formed rotatably along the rails 3 and 4. An erection 22 is erected at the edge part, on the opening 10 side, of the cover plate 21 forming the back plate of a containing part throughout the containing device and the ceiling closet. A distance between the top plate 1 and the bottom plate 2 of the containing device and a distance between the upper and lower rails 3 and 4 are kept and the frame 6 can be stably moved for a long period and a containing function can be stably maintained for a long period by means of the erection 22.