The present invention relates to a device for treating substrates which device is modular and versatile in use. The device for treating substrates comprises a feeder and one or more first sub-structure modules which each comprise a pressure cylinder with devices for fixing a lift and a sheet-conveying device and one or more second sub-structure modules which respectively have a transport cylinder with openings formed on the cover surface thereof, and having devices for fixing a lift and a sheet conveying device. All of the first or second sub-structure modules have the same intersection point for connecting the sub-structure modules on one of the inlet and the exit side and they all can be equipped with an attachment module.