A plurality of cutting tips are mounted on the distal end of the cylindrical main body of a drilling tool for performing trepanning. These tips are disposed along the circumferential direction of the main body and equidistantly spaced apart from one another. The force, which is produced by all of the cutting tips and acting at right angles to the axis of the main body, is smaller than the component of the cutting force, which is produced by each tip and acting at right angles to the axis of the main body. The cutting widths of the tips in the radial direction of the main body are substantially equal. One of the tips, which is located at an intermediate position in the radial direction, has a V-shaped leading portion.