An endoscope comprising: a distal tip unit configured to be inserted into a patient's body cavity; a proximal endoscope handle comprising an operating unit for steering the distal tip unit ; an endoscope shaft connecting the endoscope handle and the distal tip unit and comprising a bending section ; a working channel provided in the endoscope shaft and extending from the endoscope handle towards the distal tip unit ; and a steering wire for controlling a bending movement of the bending section , the steering wire being connected to the operating unit and extending through the endoscope shaft ; the bending section comprising: a proximal end segment ; a plurality of intermediate segments ; a distal end segment connected to the distal tip unit ; flexible hinge members provided between adjacent segments of the proximal end segment , the plurality of intermediate segments and the distal end segment ; an inner lumen adopted for accommodating the working channel ; and steering wire lumens adapted for accommodating the steering wire ; wherein the working channel is gradually guided away from a position close to a centerline of the endoscope shaft in the bending section ; characterized in that the inner lumen of the bending section has a radially outwardly extending cut-out portion with a given depth into a material of the proximal end segment , the plurality of intermediate segments and the distal end segment between two steering wire lumens for accommodating the working channel and a depth of the cut-out portion into the material gradually increases along the bending section from the proximal end segment to the distal end segment . a distal tip unit configured to be inserted into a patient's body cavity; a proximal endoscope handle comprising an operating unit for steering the distal tip unit ; an endoscope shaft connecting the endoscope handle and the distal tip unit and comprising a bending section ; a working channel provided in the endoscope shaft and extending from the endoscope handle towards the distal tip unit ; and a steering wire for controlling a bending movement of the bending section , the steering wire being connected to the operating unit and extending through the endoscope shaft ; the bending section comprising: a proximal end segment ; a plurality of intermediate segments ; a distal end segment connected to the distal tip unit ; flexible hinge members provided between adjacent segments of the proximal end segment , the plurality of intermediate segments and the distal end segment ; an inner lumen adopted for accommodating the working channel ; and steering wire lumens adapted for accommodating the steering wire ; wherein the working channel is gradually guided away from a position close to a centerline of the endoscope shaft in the bending section ; characterized in that the inner lumen of the bending section has a radially outwardly extending cut-out portion with a given depth into a material of the proximal end segment , the plurality of intermediate segments and the distal end segment between two steering wire lumens for accommodating the working channel and a depth of the cut-out portion into the material gradually increases along the bending section from the proximal end segment to the distal end segment . <EOS>