To provide a boring tool capable of improving working efficiency of hole machining.

A plurality of chamfering parts 15 arranged along the circumferential direction of a shaft body at equal intervals are provided in a corner of the tip part. A recessed groove 17 is extended along the axial direction of the shaft body on the side face of the shaft body corresponding to the chamfering part 15. Opening ends 19, 20 of a circulation hole for feeding a grinding fluid are arranged so as to partially face the chamfering part 15.