PURPOSE: To efficiently polish the inner surfaces of a plurality of pipes, by providing such an arrangement that a plurality of rod members attached, in the intermediate sections thereof, with polishing tools, are laid in parallel with each other, and the pipes inserted respectively onto the rod members are carried by a reciprocating carrier bed to be reciprocated.

CONSTITUTION: Pipes (a) to be polished, to which polishing tools 7 having a diameter corresponding to the inner diameter of the pipe (a) are respectively attached from end hook 4 side of rod member 3 being fitted into holders 21 at both ends, are inserted onto rod members 3. Further both end holders 21 are fitted into pipe lock recesses 17 in front and rear support frames 15, 16 on a carrier bed frame 14, and as well the front end hooks 4 which project from opening ends of the pipes (a), are latched to hooks 5 on a rear frame 2. In this condition, by driving a motor to reciprocate the carrier bed frame 14 under the control of limit switches 24, 25, the inner surfaces of the pipes (a) are polished by the polishing tools 7.