PURPOSE: To effectively utilize the inside space in accordance with the size of stored things without loss of space by erecting posts in the inside of a storage and fitting multi-stage shelves which are adjustable in height on the posts.

CONSTITUTION: A fitting part 63 is provided at the center of a base plate 61 of a shelf 6. The shelf 6 is fitted to a post 5 through a height-adjustable member 7. When the height is changed, the shelf 6 is raised and the height-adjustable member 7 is vertically moved. In this case, a fitting protrusion 72 is fitted in the other fitting groove 51 to temporarily fix it. And then the shelf 6 is lowered and the fitting part 63 is again fitted outwardly on the height-adjusting member 7 and fixed so as not to widen the height-adjusting member 7.