The purpose of the present invention is to provide a bending angle adjustment mechanism which achieves reduction of the number of components and unitizes the mechanism, contributes to simplification of the assembly process and reduction of manufacturing costs, and contributes to improving the working efficiency of re-adjustment during overhauling. This bending angle adjustment mechanism (30) of an endoscope (1) is provided with: a rod member (54) provided so as to extend in the length direction of an insertion unit (2) and comprising a threaded portion formed on the longitudinal surface； a plate member (52) which is disposed parallel with the longitudinal direction of the rod member and through which the rod member is inserted at both ends, which are bent in an approximately perpendicular direction； an adjustment piece (55) which screws together with the threaded portion of the rod member； a guide member (53) which is arranged parallel with the rod member and the plate member and which comprises, disposed in the longitudinal direction of the insertion unit, a guide path (53xb) through which a long member (32) passes and a guide path (53xa) which guides the adjustment piece； and a rotation stopping member (51) which keeps the rod member from rotating relative to the guide member about an axis in the longitudinal direction. At least one surface non-parallel with the guide surface of the guide member is fixed between the adjustment piece and the plate member.L'objet de la présente invention consiste à proposer un mécanisme d'ajustement d'angle de courbure qui permet de réduire le nombre d'éléments et unifie le mécanisme, participe à la simplification du processus d'assemblage et à la réduction des coûts de fabrication et participe à l'amélioration de l'efficacité du travail de réajustement pendant la révision. Ledit mécanisme d'ajustement (30) d'angle de courbure d'un endoscope (1) est doté : d'un élément de tige (54) formé de façon à s'étendre dans le sens de la longu
