PURPOSE: To omit the works to process standard-size panels at site when matching the sizes at local site and reduce the working processes, by forming the distance between a couple of opposite sides to make nearly equal in the main planes of the first and the second panels and providing the fitting part of the second panel on the first panel.

CONSTITUTION: An electromagnetic wave-shield room is constituted of standard size panels 10, adjusting panels 60, panels 70 with a window, posts, etc. The adjusting panels 60 are constituted of the first panel 60a and the second panel 60b. The width of the main plane 61b and the upper and lower peripheral plates 63b of the second panel 60b are decided to be able to insert the second panel 60b from one side of the main plane of the first panel 60a. When the adjusting panels are set, the first panel 60a is rivetted in the posts. Next, the second panel 60b is drawn from the first panel 60a and the side peripheral plate 64b thereof is forced to contact the peripheral plate of the panel 70 with windows to joint them together with rivets. Moreover, the overlapped part of the first panel 60a and the second panel 60b is also jointed with rivets to increase tightness. For rivetting, rivet holes 18, 69b are previously bored in peripheral panels 12, 64b to contact tight the mutual peripheral panels. In this way, a plurality of panels 10, 60, 70 are jointed to each other.