A slender insertion section of the endoscope has an endoscope distal-end portion, a tubular body and a bending portion, all extending along the longitudinal axis of the insertion section. The bending portion is arranged between the distal-end portion and the tubular body. The insertion section has an inner component. The bending portion has an annular ring assembly composed of a plurality of annular rings arranged side by side. Each annular ring has a ring body, a pair of bulging portion that face at one end face of the ring body, and a plurality of projections which the inner component can move. The most distal annular ring of the annular ring assembly supports one end of a wire. The wire passes through the annular rings and has its other end coupled to an operation section of the endoscope.
