PURPOSE: To make an opening with a firm structure and increase the workability, by jointing a wall panel, the upper panel, and the frame member through jointing metal fixtures composed of columns and joints, in an opening formed on the wall of a bath room.

CONSTITUTION: This structure is provided with a jointing metal fixture 4 composed of a flat column 4B extending downward and a unified joint 4A at the upper end thereof and a jointing metal fixture 5 composed of a L-shaped column 5B extending downward and a unified joint plate 5A at the upper end thereof. A wall panel 1, an upper panel 2, a door frame 3 or a window frame are easily and firmly connected to each other through the jointing metal fixtures 4, 5 in the opening K like a door or a window on the wall of a bath room formed by erecting extruded cement boards.