PURPOSE: To obtain the device stated in the title as small type at low cost by connecting at least two moving units together via a freely expanding and contracting connecting means, and providing means for freely setting each moving unit to its movable state wherein the unit is movable along a surface and to its engaged state wherein it is engaged in the surface.
CONSTITUTION: A surface moving device comprises a pair of front and rear moving units 2A, 2B connected to each other by a freely expanding and contracting connecting means 66 including a pair of cylinder mechanisms 68, 70. Each moving unit 2A, 2B has a member 22 made from synthetic rubber etc., consisting of a tubular base portion 24 and a seal portion 26 and provided on a tubular vertical wall 20 extending downward from a circular opening 18 formed in the lower wall 16 of a main body 4 in the form of a hollow parallelepiped, the seal portion 26 extending in the radially outward direction from the outer peripheral face of the tubular base portion 24. An air pressure cylinder mechanism 46 is installed at the main body 4 and a running means 52 is provided at the end portion of the rod 50 of the mechanism 46, which end portion protrudes into a pressure reduction space 38. The pressure reduction space 38 is connected to a pressure reducing source via a communicating opening 40 and a communicating tube 42.