PURPOSE: To improve the using rate of a space by providing the internal surface upper-sections of the external wall panel of a PC plate with upper section fasteners to be jointed to the upper section flanges of steel frame beams, and by providing the internal surface intermediate sections with lower section fasteners to be jointed to the webs of the beams.

CONSTITUTION: The left and right upper-sections of a PC plate external-wall panel A are provided with upper section fasteners 1, and the left and right lower-sections are provided with lower section fasteners 2, and they are fitted on the upper section flanges Ba and webs Bb of steel frame beams B. After that, the respective horizontal sections 113 of the L-shaped plates 11 of the upper section fasteners 1 are positioned on the upper section flanges Ba of the steel frame beams B, and the exterior panel A is positioned in the vertical and horizontal directions with level regulating bolts. After that, with the fixing bolts 29 of the angle members 23 of the lower section fasteners 2, and position regulating bolts 26, positions are regulated in the horizontal direction. As a result, the regulation can be facilitated with devices.