Abstract: A grinding bar capable of stably staying a grinding part in a minute part of an affected part to execute a grinding and treatment in an environment having a large visual field is provided. This grinding bar to be mounted on a hand piece and used for grinding a tooth comprises a shank part 12 to be mounted on the hand piece, a tapered neck part 13 provided continuously to the shank part 12, a rod part B provided continuously to the neck part 13 and narrower and longer than the neck part 13, and an arrowhead-like or piece-like grinding part 15 formed by fixing diamond particles to the tip of the rod part B.