To effectively provide an increased life for a tool as a sufficient strength is kept.

In a drill wherein a body clearance 3 having diameter smaller than the size of a margin with a margin 2 left at an outer peripheral surface, the depth of the body clearance 3 is gradually increased away from the margin 2. More preferably, the surface of a drill is coated with a hard film. Thus, even when wear of the tip corner part of a margin 2 is progressed and attains the depth level of the body clearance 3, since the body clearance 3 is formed in a shape that with the progress of separation of it from the margin 2, the body clearance is escaped to the radial inside, this constitution suppresses the progress of wear in a peripheral direction along the tip corner part of the body clearance 3, and during this, wear of the tip of the margin 2 is locally progressed.