The drill of the present invention has only one cutting discharge groove (11) formed in the outer periphery of a bit (10). A leading edge protruding farthest towards the tip in the axial direction in a tip flank (12) is composed at a single point and located on an axis (O). When bit is viewed from the tip side in the direction of axis, tip flank is in the form of a multilevel surface composed of second through fourth flanks (14B, 14C and 14D) arranged along the peripheral direction, and a reverse side first flank (14E) surrounded by second through fourth flanks and intersecting with axis.
