PURPOSE: To fix an expanding member to an undercut member by forming an undercut part to the bottom part of a drill hole by the circulation motion of a drill bit to an immovable facade panel or the circular motion of a panel to an immovable drill bit.

CONSTITUTION: When a drill is allowed to fall on a facade panel or the facade panel is raised to the drill, a plurality of drill holes 10 are drilled in the facade panel 1. Further, when drill bits 2 come into contact with the bottom parts of the drill holes, undercut parts are formed to the bottom parts of the drill holes 10 by the rotation of the drill bits 2 or the facade panel 1. When bolts 6 are screwed in a disc 7 and the expanded segments 8 attached to the disc 7, the expanded segments 8 are expanded to be immovably fixed in the drill holes 10. In this case, when an adhesive is injected into the conically expanded drill holes 10, the expanded segments 8 are certainly fixed.