Abstract: A deskewing device for a moving web of material in a corrugated cardboard manufacturing system incorporates a plurality of successive processing units that are equipped with processing tools, which are movable crosswise to the direction of conveyance of the web of material. A skew measuring device is provided to determine the skew of the web of material. It has a first position sensor, at least one second position sensor, which determine the transverse position of the web of material at predetermined longitudinal positions. A control unit is used to calculate from the data of the position sensors the skew of the web of material and the transverse position of the processing tools is corrected accordingly.