To provide a suction cup capable of stably adhering to a window, a wall or the like and movable while adhering to it, and a wall surface moving machine adopting the suction cup.

The suction cup includes: a body part 11 having a recess 11h recessed from one surface; and space maintaining members 15 providing restrictions so that the one surface and an inner bottom face 11s of the recess 11h do not come closer to each other and a predetermined distance or longer is left between them. A friction reduction part reducing friction resistance is installed on a contact surface on the one face side of the space maintaining member 15. The space maintaining member 15 is arranged so that a distance from the contact surface to the inner bottom face 11s of the recess 11h is set shorter than a distance from the one face of the body 11 to the inner bottom face 11s of the recess 11h.