To provide an OA(office automation) equipment base which can be quickly installed and also to secure the effective use of spaces in office room.

A surrounding wall 4 is prepared in a vertical square cylinder shape. A bottom plate 5 is attached fallingly from above inside the wall 4 and attached there, so that the wall 4 is kept open in a square columnar shape. A top plate 6 is placed at the upper end part of the wall 4 surroundingly from above. An articles store room 7 is surrounded by the wall 4 and both plates 5 and 6. Thus, the wall 4 can be freely folded into a plate-like shape and also expanded into a square columnar shape.