PROBLEM TO BE SOLVED: To provide a toothbrush capable of achieving excellent operability and a proper brushing pressure.SOLUTION: In a toothbrush including a head part 2 formed by planting a hair bundle on a bristle implanting face 20, a neck part 4 installed elongatively from the head part, and a handle part installed elongatively from the neck part, a cross-sectional shape of a region having the smallest flexure strength at least on the neck part has a contour including each apex arranged respectively on the positions of a first apex to a third apex forming a triangle, and a line part for connecting each apex, and a line segment connecting the first apex to the second apex is parallel to the bristle implanting face.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2018,JPO&INPIT【課題】良好な操作性および適切なブラッシング圧を実現できる歯ブラシを提供する。【解決手段】植毛面20に毛束が植設されたヘッド部2と、ヘッド部に延設されたネック部4と、ネック部に延設されたハンドル部とを備え、少なくとも前記ネック部における最も曲げ強度が小さい領域の断面形状は、三角形を形成する第1頂点~第3頂点の位置にそれぞれ配置された頂部と、頂部間を結ぶ線部とを含む輪郭を有し、第1頂点と第2頂点とを結ぶ線分は、植毛面と平行である。【選択図】図3
