To provide a micro rotating tool exhibiting sufficient performance in both machining performance and the service lifetime of a tool even to the machining of a material called a ferrous or glass-based hard-to-cut material difficult to be machined even by a diamond tool.

The micro rotating tool 1 has an axisymmetrical shank part 2 composed of a cemented carbide material, and a bit part 3 composed of a binderless fine-grained high-purity CBN polycrystalline substance material and joined to the end face of the shank part 2 concentrically with the central axis 21 of the shank part. A multi-edge tip cutting edge 31, in which a plurality of square drills 32 are densely and adjacently aligned to each other, is formed at the end face opposite to the side where the bit part 3 is joined with the shank part 2. Two mutually facing drill planes 33 of the two square drills 32 adjacent to each other cross with each other at an angle of 60 degrees ±5 degrees in the square drills 32. Individual square drills 32 are aligned at a pitch of 0.06-0.1 mm in two alignment directions orthogonal to each other.