An endoscope preferably comprising an alternating propulsion system in which an endoscope shaft is advanced by means of an auxiliary means (e.g. a hose preferably including fluid pads or a guiding wire/net) in a canal-shaped cavity by the fact that the endoscope shaft and the auxiliary means are alternately resting with respect to a cavity to be inspected and, at the same time, the element not at rest can be advanced while being guided along the resting element into the cavity, or are simultaneously moved forward, wherein in the latter case the basic stiffness of the auxiliary means is higher than that of the shaft.
