PURPOSE: To perform enough chamfering with high efficiency, by a method wherein an object to be machined is contained in a cone-shaped recessed part of a grinding stone supporting body, to the cone-shaped inner peripheral surface of which a grinding actuating body is attached, and after the outer peripheral part of the grinding stone supporting body is surrounded with a cylinder body, the grinding stone supporting body is rotated.

CONSTITUTION: With a cover body 14 raised, objects W to be machined are contained on the recessed part of a grinding stone supporting body 7. The cover body 14 is then lowered. Thereafter, polishing liquid 3 is fed through nozzles 17, and with a motor started, a base plate 6 is rotated. In which case, the objects W to be machined are raised along a slope against its own weight through the action of a centrifugal force, and are attracted to the cylinder body 15 side. The works W to be machined are rotated integrally with the base plate 6 as they are rolled over a grinding stone 8. During this process, the works W are chamfered by the grinding stone 8, and are also chamfered by a square columnar grinding stone pieces 16 attached to the cylinder body 15. This constitution enables uniform chamfering of the works W to be machined, and improves chamfering efficiency.