Abstract: A caterpillar device includes: a water film removing part which is provided in a power transmission member including chains, presses and removes a water film between an attachment object as a magnetic material, and the power transmission member with a magnetic force, and attaches the power transmission member to the attachment object to secure a frictional force; and an apparatus body magnet attachment part which is connected to the power transmission member and attaches the body of the apparatus to the attachment object.

Abstract: A magnetic wheel includes: a balance block; a magnetic body which is provided in the balance block and attaches the balance block to an attachment object with a magnetic force; and a magnetic shielding block which is provided in the balance block and guides a magnetic field generated in the magnetic body toward the attachment object.

Abstract: A load distribution apparatus of magnetic wheel, includes: a plurality of cylinder parts including one sides respectively connected to a plurality of magnetic wheels and an upper space portion and a lower space portion whose interiors do not communicate to each other; and a passage part which serves as a moving path of fluid and interconnects the plurality of cylinder parts. The passage part is configured to evenly distribute a load applied to the magnetic wheels by moving fluids in the upper space portion and the lower space portion in such a manner that the fluids are not mixed.