PROBLEM TO BE SOLVED: To provide a file for interdental grinding, which can be easily and surely inserted between teeth and can be moved with a smaller force, and an interdental grinding device provided with the file. A file 1 for interdental grinding for forming a required space between teeth, in which front and back surfaces 2A and 2B of a base material 2 are ground surfaces 3 to which hard fine particles for grinding are attached. , Non-grinding surfaces 51 to 59 to which hard particles are not adhered are provided, and as non-grinding surfaces, non-grinding surfaces formed in a vertically long strip shape penetrating in the width direction at approximately the center in the longitudinal direction of the base material. The central slit portion 6 having 51, and the left slit portion 7 and the right slit portion 8 each having a non-ground surface formed with one or a plurality of slits on both sides (left and right sides) of the central slit portion 6 are provided. [Selection diagram] Figure 1【課題】歯間に簡単かつ確実に挿し込むことができ、かつ、より小さな力でヤスリを動かすことが可能となる歯間研削用のヤスリ及びそれを備える歯間研削装置を提供する。【解決手段】歯間に所要のスペースを形成するための歯間研削用のヤスリ１であって、基材２の表裏面２Ａ，２Ｂに、研削用の硬質微粒子を付着させた研削面３と、硬質微粒子を付着させていない非研削面５１～５９とが設けられており、非研削面として、基材の長手方向の略中央において幅方向に貫通する縦長の帯状に形成された非研削面５１を有する中央スリット部６と、中央スリット部６の両側（左右両側）それぞれに一本又は複数本ずつが形成された非研削面を有する左スリット部７及び右スリット部８とを備える。【選択図】図１
