To prevent removal from a support of a support cover even when the strong force of peeling-off from the support is applied to the support cover.

A plurality of upward engaging pieces 10 are projected at intervals in the vertical direction extending over the approximately overall height of the outer side face 3a of a support 3 installed at the side end section of a partition panel body 1 and directed in the vertical direction. Mutually faced abutting pieces 15 are formed at the interior ends of the front-rear outward receiving pieces 14, 14 of a fitting groove 13 in the support cover 11 having the fitting groove 13 capable of being fitted to the outer side section of the support 3 in an inner side face 12 at that time, the abutting pieces 15 are abutted against the outer side face 3a of the support 3, and engaging sections 15a formed by notching parts of the abutting pieces 15 are engaged with the upward engaging pieces 10.