In this paper, an in-pipe mobile robot is developed, which is composed of two types of soft actuators. One is a traveling actuator that can be expanded to its axial direction, the other is a holding actuator that can be expanded to its radial direction. These actuators are made of a silicon rubber and are driven with a pneumatic power. The holding actuator can adaptively change its shape owing to the flexibility of the silicon rubber and the air pressure. Therefore, the robot can travel in various types of pipes, such as changing diameter at a joint, wiring in a pipe, and pipe with an arbitrary sectional shape. Because the whole body of robot is elastic, this robot doesn't make a damage for the pipe wall and can travel in an elastic pipe. Because the robot is simply structured, it is easy to be scaled down. These features are expected for traveling in a living body. The influence of the tube length (from servo valve to robot) is compensated by an improved control system. The compensator composes the transfer function that is identified the pressure response of robot and tube. In case of the pipe has fluid flow, the holding actuators are added the passage pipe, this robot can travel in such a pipe. The validity of this robot is confirmed through some experiments.