The endoscope 1 includes an objective optical unit 10U including a distal optical lens 13 and an objective lens frame 10, an illumination optical system 20 including an illumination lens 21, and a distal end body 31 constituting the distal end 6. The lens frame 10C includes a first lens frame 11 and a second lens frame 12, and the first lens frame 11 is provided with an arrangement hole 11h, an inward convex portion 11a, and an outward convex portion 11b. Is provided with a receiving hole 12h, and the light incident surface 13f and the first tip surface 11f are arranged on the same plane with the chamfered surface of the chamfered portion 13c in contact with the lens positioning surface 11e of the inwardly convex portion 11a. The first tip surface 11f and the second tip surface 12f are arranged on the same plane with the first frame positioning surface 11d in surface contact with the objective optical unit positioning surface 12u.内視鏡１は、先端光学レンズ１３及び対物レンズ枠１０を備える対物光学ユニット１０Ｕと、照明レンズ２１を備える照明光学系２０と、先端部６を構成する先端部本体３１とを具備し、対物レンズ枠１０Ｃは第１レンズ枠１１と第２レンズ枠１２を備え、第１レンズ枠１１には配設孔１１ｈと内方凸部１１ａと外方凸部１１ｂが設けられ、第２レンズ枠１２には収容孔１２ｈが設けられ、光入射面１３ｆと第１先端面１１ｆは面取り部１３ｃの面取り面が内方凸部１１ａのレンズ位置決め面１１ｅに面接触して同一平面上に配置され、第１先端面１１ｆと第２先端面１２ｆは第１枠位置決め面１１ｄが対物光学ユニット位置決め面１２ｕに面接触して同一平面上に配置される。
