PURPOSE: To increase stability by connecting a flexible and elastically movable thin piece arranged with a certain distance from an edge portion or a ridge portion and having a fixed region in its inner surface to the bottom surface of a relatively rigid holding member having bending resistance.

CONSTITUTION: A flexible or elastically movable plate piece or a thin piece 2 made of, e.g. rubber, a synthetic material or the like is connected to the bottom surface of a relatively rigid holding member 1 having bending resistance via a fixed area 5 in the bottom surface of a holding, retaining and adsorbing means, e.g. by means of gluing or sulfidization method. When a traction force Z, tilting or a inverting force H is applied to the holding member 1 placed on a foundation bed 16, the material of a peripheral protruded portion 4 provided between the edge or the ridge line 6 of the thin piece 2 and the fixed area 5 is firmly adhered to the foundation bed surface 16 by vacuum generated by the force and, to secure its adsorbing effect, a concave vacuum state is generated in a contact surface 7. This adsorbing force is released by an ear piece 17 or the like.