To provide a restoring method for a small-sized drill, which enables restored use, and also to provide a product thereof.

In the step (a), the small-sized drill having a shank, a conical connecting part and a first cutting part are prepared. The shank is held in a drilling machine. The conical connecting part is connected to the upside of one end, and has a smaller outside diameter than the shank, and the first cutting part is connected to the upside of the free end of the conical connecting part. The first cutting part wears away to a predetermined degree. In the step (b), the first cutting part is removed. In the step (c), a joint part having a smaller outside diameter than the shank is formed on the upside of the free end of the shank. In the step (d), a joining unit having an outside diameter equal to that of the shank is prepared, a joining vessel is formed along the axial direction in the joining unit, and the joint part is inserted in the joining vessel and tightly fixed. In the step (e), a second cutting part is formed on the conical connecting part, and the second cutting part is provided with a small blade part and groove. The blade part is used for drilling work on a circuit board, and the groove provides a space for eliminating waste in drilling.