To form a fine wall surface by setting the dimension between the side edges of adjacent panel bodies of panels laterally spliced to the front and rear faces of a frame body formed of longitudinal frame members and lateral frame members, twice the dimension between the outer side edge of the panel body arranged at the end part and the outer side edge of the frame body.

A panel body 21 is made of sheet metal formed in U-shape with both lateral edges bent backward and with upper and lower ends formed as open ends 21C, and insert ends 32 are formed at one ends of edge members 3A, 3B formed of synthetic resin. The insert ends 32 of the edge members 3A, 3B are inserted in the open ends 21c of the panel body 21 so that the surfaces of the edge members 3A, 3B and panel body 21 are flush with each other, and engaging claws 31a, 31b are fitted to the edge members 3A, 3B. At the time of fitting the panel body 21 to a frame body, the engaging claws 31a are engaged into engaging holes of a lower lateral frame member, and the engaging claws 31b are engagedly fitted into engaging holes of an upper lateral frame member using elastic deformation. A fine continuous wall surface can therefore be formed.