To provide a drill grinding method which can generate a sharp crest in the conical rotating locus of each cutting edge at the tip of a drill.

In the central cutting edge forming process, a pair of central cutting edges 16a and 16b constituting a convex arc of circle having a radius approx. 25-35% of the drill diameter are formed in point symmetry by means of thinning process in the rotational direction in the neighborhood of the rotational center O; in the straight cutting edge forming process, straight cutting edges 18a and 18b are formed as stretching straight to the peripheral end in continuity to the central cutting edges 16a and 16b. Accordingly there is no concave at the crests in the conical rotating loci of cutting edges 14a and 14b located at the tip of the drill 10, and a sharp crest form is established. This eliminates the problem of axis deflection at the time of starting the boring operation with a drill.