An endoscope includes an insertion section including an insertion main body extended along a longitudinal axis, and an attachment unit provided to an outer peripheral direction side of the insertion section and rotatable about the longitudinal axis with respect to the insertion main body. The attachment unit includes a tube main body extended along the longitudinal axis in a state that a gap is provided between itself and an outer peripheral portion of the insertion section or a member disposed on the outer peripheral portion of the insertion section, a fin portion spirally extended on an outer peripheral portion of the tube main body along the longitudinal axis, and a tube distal end portion provided from a distal end of the attachment unit toward a proximal direction and made of a material softer than the tube main body. The tube distal end portion includes a distal side gap reducing portion eliminating the gap or to reducing the gap to be smaller than a part to an inner peripheral direction side of the tube main body between the attachment unit and the outer peripheral portion of the insertion section or the member disposed on the outer peripheral portion of the insertion section.
