PURPOSE: To change the number of shelf members and the relative positions of respective shelf members and partition members as occasion demands by engaging the shelf members and the partition members so as to be relatively movable in the longitudinal direction of the shelf members, so that the shelf members and the partition members can be freely combined.

CONSTITUTION: First, a first-step shelf member 1 being placed at the lowest position is put on shelf members 11. Next, two partition members 2 are fitted on the shelf member 1 respectively, in such a way that the lockedly engaging member 6 on the one side of partition member 2 is insertedly fitted in the guide groove 5 which has been formed on the upper surface side of the first-step shelf member 1. Then, another shelf member 1 as a second step is stacked in such a way that the lockedly engaging members 6 positioned on the other sides or the upper ends of the two partition members 2 are insertedly fitted into the guide grooves 5 formed on the undersurface side thereof. Thus, since the respective shelf members 1 and partition members 2 are engaged with each other so as to be relatively movable, partially large housing spaces in the upward direction can be secured. And by contriving the relative positions, the shelf can be installed even in such a room under a stairway whose wall is restricted by the sloped surface of stairs.