An endoscope comprising a flexible catheter probe 1 having a plurality of lumens, a handle 12 provided at the proximal end of the probe, an optical system 6 provided in at least one optical system lumen of the catheter probe 1, at least one working lumen for a surgical instrument and a control element which is fixed to the distal end 20 of the probe or in the proximity thereof for bending the end of the probe and is guided movably in the axial direction at the probe, wherein the optical system 6 which projects beyond the proximal end of the catheter probe 1 is guided in a flexible tube which is elastically resilient in its longitudinal direction and exerts a prestressing on the optical system in the longitudinal direction thereof in a direction towards the translucently closed optical system lumen.