To solve the existing problem that a panel might be bowed and fall down because of an extraordinary load sustained by the panel, when the low partition panel holds a top plate jutting out in a direction perpendicular to the surface of the low partition panel.

When a top plate 1 to put objects such as an office automation equipment is attached to a panel 2 with the top plate 1 protruded in a direction perpendicular to the surface of the panel 2, an upper end 2a of the panel 2 is secured to and supported by a ceiling surface C, and a lower end 2b thereof is secured to and supported by a floor F.