An endoscope 1 includes: an insertion portion 2 in which a distal end portion 6 and a bending portion 7 are arranged and an inclined face 24 that is formed in the distal end portion 6, the inclined face 24 being formed so as to inclinedly intersect with each side face adjoining a distal end face 20a of the distal end portion 6, and being formed substantially orthogonal to a ridge line 24a formed intersecting with the distal end face 20a and to a direction in which the bending portion 7 bends. By contacting against an inner wall of a curved portion of a duct 100 into which the insertion portion 2 is inserted, the inclined face varies a posture thereof so that the insertion portion 2 is rotated and a bending direction of the bending portion 7 matches a curving direction of the curved portion. Thus, the ability of the bending portion of the insertion portion to pass through a curved duct can be improved by means of a simple configuration that does not increase the manufacturing cost.
