To provide a sensible high-functional toothbrush, having higher elastic recovery as compared with the conventional nylon and low hygroscopicity, and having durability and excellent massage effect without damaging the gum in a long-time use.

In this brush planted with bristles formed by a monofilament mainly composed of polyester A having a propylene terephthalate as a main repeated unit, the limiting viscosity of the polyester A is 0.5 or higher, and the carboxyl terminal group concentration is 20 equivalent/ton or lower.