PROBLEM TO BE SOLVED: To provide an interdental brush which has an excellent durability and a sufficient cleaning effect even after repeated use, and also to provide a method of manufacturing an interdental brush.SOLUTION: An interdental brush according to the present invention comprises: a head part having a length in an axial direction and having a brush part about an axis； and a handle part connected to one end side of the head part in an axial direction. The head part includes: a hard resin member having a first portion and a second portion arranged in the axial direction； a soft resin member axially covering the first portion of the hard resin member； and an insert portion including the second portion of the hard resin member and at least a part of an edge portion of the soft resin member on the second portion side. The handle part has a head holding portion that covers at least the entire insert portion of the head part from the radial outside. The structure of the connection between the head part and the handle part has a three-layer structure including the hard resin member in the insert portion of the head part, the soft resin member, and the head holding portion in the handle part.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】本発明は、耐久性に優れ、繰り返しの使用においても十分な清掃効果が得られる歯間ブラシおよび歯間ブラシの製造方法を提供する。【解決手段】本発明の歯間ブラシは、軸方向に長さを有するとともに軸回りにブラシ部を有するヘッド部と、ヘッド部の軸方向の一端側に接続されるハンドル部と、を備え、ヘッド部は、軸方向に並ぶ第１部分および第２部分を有する硬質樹脂部材と、硬質樹脂部材の第１部分を軸回りに覆う軟質樹脂部材と、を有し、硬質樹脂部材の第２部分と、軟質樹脂部材の第２部分側の少なくとも一部の端縁部と、からなるインサート部と、を有し、ハンドル部は、ヘッド部のうち少なくともインサート部の全体を径方向外側から覆うヘッド保持部を有しており、ヘッド部とハンドル部との接続部分の構造が、ヘッド部のインサート部における硬質樹脂部材と、軟質樹脂部材と、ハンドル部におけるヘッド保持部と、からなる３層構造とされている。【選択図】図１
