An apparatus for determining the position of a hollow section system which is pressed forward. Measuring apparatus are arranged one behind the other in the hollow section system. Measuring points are also provided. Each measuring apparatus has a light source for marking the position, a position detector, and an optical system. The measuring apparatus are arranged in such a way that the projection of the light source of each measuring apparatus takes place to the position detector of the respective adjacent measuring apparatus. The measuring apparatus are connected to each other for the transmission, and receiving, of signals present at the position detectors. The coordinates of the measuring apparatus can be determined from the signals, and from this the spatial position of the hollow section system can be determined.