For installation, a cable (5, 17) or empty pipe is anchored in a canal or pipe system (1, 3) at a minimum of 2 anchoring points (2) along the longitudinal direction of the canal or pipe system. The cable (5, 17) or an empty pipe and at least one holding device (12, 21) fastened to the inner wall (16) of the canal or pipe system are installed in the area of a branch point (6) in such a way, that the cable or empty pipe are guided around the branch point by means of the holding device and due to their defined pre-tension. The installation can be done comparatively quickly and easily, and after installation the function of the branch point, for example, in the form of an inlet canal, is not diminished.