The invention provides an endoscope capable of improving operatability in assembling. When an installation sheet (69) is inserted in an installation sheet insertion slot (82), a front end part of a thick wall part (67) is embedded with a thick wall part accommodating groove (81), and a connecting cylinder (53) is positioned in a circumferential direction relative to a front end part main body (51). A front end face of the thick wall part (67) abuts against a front end face (81a) of the thick wall part accommodating groove (81), and the connecting cylinder (53) is positioned in a cylinder center direction relative to the front end part main body (51). A mounting screw (88) is in threaded engagement with a threaded hole (83) of the installation sheet insertion slot (82) via a gap (52a) of a front end cover (52) and a screw insertion hole (69a) of the installation sheet (69), and the connecting cylinder (53) is fixed to the front end part main body (51). Assembling and fixing of the connecting cylinder (53) towards the front end part main body (51) can be performed in a simple and reliable manner.
