PURPOSE:To perform grinding/polishing conveniently without requiring large scale facility by functioning a grinding/polishing machine for removing flaw on the working face caused by NC machine tool while profiling the random curved face of workpiece. CONSTITUTION:Upon function of pressure controllers 12, 13 and a flow controller 14, a grinding/polishing tool 6 will move up and down while rotating. In other word, pressure medium will function from the pressure controller 12 through an air hole 8 to the push space 17 while from the pressure controller 13 through an air hole 9 to the rull space 18. Pressure air will function from the flow controller 14 through air holes 10, 11 onto a turbine 7 to apply rotation to said tool 6, but the axial position will depend on the position of a pressure receiving board 5 in the cylinder 2. Said systems are bundled and fixed by a band 19 then pressed against a workpiece 20 having random curved face thereafter the workpiece 20 is moved back/fro and left/right to feed out the grinding/ polishing tool 6 within the operating range of the rotary shaft 4 or pressure receiving board 5.