Abstract: A device (1) for registering data and features of ducts includes at least one camera (3, 5), at least one distance measurement apparatus and at least one apparatus for measuring properties of the medium contained in the duct. Furthermore, provision can be made for an illumination apparatus (4), a tracking sensor (10), which emits data in relation to the current position of the device (1), and an inclination measurement device (inclinometer and gyroscopic compass 9). The device can have a passive or active drive for moving the device (1) along the duct. The device (1) can register a length recording of the duct with the aid of photo geometry or with sound, radar, acceleration sensors and/or mechanical distance measurements. Thus, after a duct has been inspected, each point can be assigned precisely in terms of length.