To easily polish the whole breadth area of a cutting edge part by forming a cavity part of a cylindrical body in round columnar shape; forming the inner peripheral surface of the cylindrical body as a polishing surface, and providing the cylindrical body rotatably with its penetrating direction as an axial direction.

A cylindrical body 7 is rotatably held by all of first guide rollers 6 and rotated by a driving roller 4. A second guide roller abuts on the upper side of the cylindrical body 7 to prevent the cylindrical body 7 from floating suddenly upward during rotation. Because of the cylindrical shape of the cylindrical body 7, a cavity part 13 is formed in columnar shape uniform in thickness, and a sand paper 14 which is a polishing surface is bonded to the inner peripheral surface. The whole length in the piercing direction of the cylindrical body 7 formed shorter than the whole longitudinal length of a cutting edge body 16 of scissors 15, and the roundness of the inner peripheral surface is set to be not less than the roundness maximum diameter in the breadth direction of the surface of the cutting edge body 16. A cutting edge part 17 is laterally rocked while pressing the surface of the cutting edge part 17 to the sand paper 14 stuck to the rotating cylindrical body 7, and ground inclining subtly forward and backward with a horizontal direction as a reference.