To fix a gel sheet made sheet on a rough surface, and simplify attaching and detaching operations by sticking the gel sheet made sheet on an adsorptive surface of a suction cup or an object material.

An auxiliary sheet 2 having suitable thickness and size is manufactured by a gel sheet (olefin elastomer) or a raw material having the same property as the gel sheet, it is stuck on an adsorptive surface of a suction cup 1 or an object material utilizing adhesion of the raw material, and the suction cup 1 is installed holding the sheet 2 between the adsorptive surface and the object material. The sheet 2 is formed in a circular shape to improve an efficiency, but it may be formed in any shapes even it has a sufficient size for fixing. When the suction cup 1 is installed in the case where the sheet 2 is thicker excessively, movement is enlarged. On the other hand, in the case where the sheet 2 is thinner excessively, it not correspond to the case where a rugged degree is large. Since a clearance between the adsorptive surface and the rugged surface of the object material surface is filled by the gel sheet, air is not invaded an inside. Therefor, the suction cup 1 is simply stuck on the object material whose surface is the rugged surface.