PURPOSE: To stably move against a wall having the surface of optional inclination or curvature by providing a bellows supporting a suction cup and having a vacuum forming chamber independently of the suction cup, the vacuum forming mechanism of the bellows, and the supporting part of the bellows, and enabling the oscillating rigidity of the suction cup to change.

CONSTITUTION: A vacuum type suction cup 1 is supported with a bellow 2 which can loosen or contract, and the bellows is supported with a supporting part 3. When the suction cup 1 approaches a face to be sucked 0, the vacuum forming chamber of the suction cup 1 is released to the atmosphere, and the vacuum forming chamber of the bellows 2 is evacuated so as to contract the belows 2. As a result of this, the recessed/projecting parts of a fitting mechanism 5 between the suction cup 1 and the supporting part 3 are mutually fitted together so as to improve oscillating rigidity of the sucking device, and when the suction cup is contacted with the face 0, the vacuum forming chamber of the bellows 2 is released to the atmosphere so as to loosen the bellows by an antenna sensor 4. Next the recessed/projecting parts of the fitting mechanism are separated so as to lower rigidity, and hence the suction cup is smoothly contacted with even the face 0 having curvature or innclination.