A urological resectoscope (1) includes a tubular, metallic external stem (2) fitted with holes (3) in its distal end zone, a tubular insulating element (7, 27, 37, 47) being affixed distally to the external stem, further comprising a tubular internal stem (8) configured within the external stem and resting against it in sealing manner and an electrode support (13) longitudinally displaceable inside the internal stem and supporting a cutting loop (15) in the region of the insulating element (7, 27, 37, 47), the inside space of the internal stem (8) and the gap (12) between the stems (2, 8) being proximally connected to liquid hookups (10, 11), the insulating element (7, 27, 37, 47) being configured in longitudinally mutually overlapping manner within an affixation zone (6) and the insulating element (7, 27, 37, 47) exhibiting a wall thickness distally from the affixation zone (6) larger than the wall thickness of the external stem (2), wherein the inside diameter of the insulating element (27, 47) is the same as the inside diameter of the external stem (2).