To provide "an in-piping work device" capable of performing piping maintenance work while smoothly traveling in piping with a branch pipe part.

In each of an oscillation wheel unit and a non-oscillation wheel unit, respective piston rods of a plurality of rod non-rotation type cylinders configuring the unit are synchronously operated. In other words, protrusion of only the one piston rod is prevented. This enables avoidance of a situation in which one driven wheel is put into an immovable state by getting caught in a hole of a branch pipe part, even when one of four driven wheels attached to respective tips of the piston rods meets with the hole.