To provide a recycling manufacturing method of a fitting type microscopic bit for making use of a worn-out fitting type microscopic bit without discarding it.

The fitting type microscopic bit worn out up to a predetermined degree is taken up in a step (a). A first bit part of the bit is removed in a following step (b). An outer diameter of a shank and an outer diameter of a connecting part of the bit are respectively polished or cut up to outer diametrical dimensions of a predetermined degree. For example, an original diameter 3.175 mm of the shank is cut down to 2.0 mm, and the connecting part is cut down to a diameter 1.0 mm. A second bit part is formed on the connecting part in a following step (d).