Abstract: A wall surface attraction type moving apparatus travels on a magnetic wall surface of a large iron structure for maintenance, inspection and other purposes. The apparatus includes a moving body movable on the wall surface, front and rear wheels, permanent magnets, drive mechanisms each for moving the respective permanent magnet toward and away from the wall surface, permanent magnet position sensors, permanent magnet attraction force sensors, and obstacle sensors. If one obstacle sensor detects an obstacle appearing in the travelling path of the moving body, the corresponding drive mechanism is controlled to retract the permanent magnet which is likely to bump against the obstacle away from the wall surface while the other drive mechanisms advance the other permanent magnets which are unlikely to bump against the obstacle toward the wall surface so that the attraction force of the advanced permanent magnets are increased to supplement the reduced attraction force of the retracted permanent magnet.