To provide a method of manufacturing a bristle neck for a brush formed of synthetic fiber, which has a tapered shape at the forward end and also a conductive part on the surface, capable of remarkably improving a yield, simplifying a manufacturing process, and also extremely decreasing the amount of raw material discarded.

This manufacturing method includes: a first process of taking up fused and spun synthetic fibers to form a fiber bundle; a second process of cutting the fiber bundle vertically to the longitudinal direction to form a unit fiber bundle; a third process of forming a tapered shape at the forward end part of the fibers included in the unit fiber bundle; a fourth process of separating some of the unit fiber bundle to form a bristle neck; and a fifth process of soaking the bristle neck in a treatment bath storing a processing liquid to form a conductive part including a conductive member on the surfaces of the fibers.