To provide a robot for working in a pipe, solving the problem of an electric leakage or the like of a cutter used in a place involving moisture by using an air motor as a drive source for rotating the cutter, and capable of dealing with pipelines with various inner diameters and flexibly dealing with handling before or after pipe renovation.

The robot 1 for working in the pipe is led into the pipeline 2 to move back and forth in the pipeline 2 and to perform cutting treatment before or after pipe renovation in a stop state. A rotating shaft 4a of an electric motor 4 provided inside a body 3 is connected to a head 5 provided at the head of the body 3, to make the head 5 circumferentially turnable, and an arm 6 vertically turned around a turning shaft 5a provided at the head 5 can be operated by the vertical movement of an air cylinder 7 provided at the head 5. Further, the cutter 10 rotated by the air motor 8 provided at the tip of the arm 6 is mounted in a replaceable manner.