To efficiently pass through a bend part.

A long pushing member 1 with flexibility is connectably installed on a rear end in an in-tube moving direction, and this movable body in a tube is installed movably in a pipe B by a pressing force F acting on the rear end in the in-tube moving direction from the outside of the pipe via the long member. The pressing force can be transmitted to a tip 12 in the in-tube moving direction, and the tip is eccentric from an action centerline.