This paper describes a prototype of a new in-pipe mobile robot. A fabricated robot is structured by three rubber bellows, lots of friction rings, three springs and three electromagnetic valves. A robot is driven by pneumatic pressure and elastic force of spring. The pressure is switched by the electromagnetic valve. The pneumatic pressure is used to expand and the elastic force is used to contract the rubber bellows. The friction rings converts the expansion and contraction movement into the advancement drive. Consequently, the in-pipe mobile robot moves freely in the pipe and robot generates the traction force of 90N.