PURPOSE: To prevent falling down from a lower hemisphere of a sphere-shaped structure in a wall surface moving robot which moves on the wall surface of the sphere-shaped structure, supporting itself with a suction means.

CONSTITUTION: A pair of support frames 4 and 5 are connected ion such a fashion that they may make a relative motion while an expandable driving leg equipped with a suction means 8 to a wall surface 2 is installed to each of the support frames. In a state where either support frame is mounted to the wall surface 2 of a structure 1 with a suction means of the expandable attracting leg, the other side-support frame is arranged to make a relative motion, thereby constituting a wall surface movable robot which may move along the wall surface by alternating the motion. A pair of light and left upper winding devices 12 are installed movable on the equator of a sphere-shaped structure or around its surrounding area in the radius direction while a lower part winding device 14 is installed to the lower part of the sphere-shaped structure. A rope 13 of the paired right and left upper part winding devices and a rope 17 of the lower part winding device are fixed with the wall surface moving robot so as to support. Therefore, this construction makes is possible to support stably the robot with the ropes without causing pendulation or swing motion when the robot falls down from the wall surface.