Abstract: The present invention relates to an apparatus and a method for the fluidic inline-treatment of flat substrates with at least one process module. In particular, the invention relates to such a treatment during the gentle and controlled transport of the substrates, wherein the treatment can also just relate to the transport of the substrates. According to the invention, a process module 1 is provided which comprises a treatment chamber 2 having at least one treatment surface 7A being substantially horizontally arranged in a treatment plane 5 and being designed for the formation of a lower fluid cushion 6A, wherein two openings in the form of entry 3 and exit 4 for the linear feed-through of the substrates 22 in the same plane are assigned to the treatment surface 7A, and at least one feed device with at least one catch 10 for the controlled feed 9 of the substrates 22 within the treatment chamber 2. Furthermore, the invention provides a method using the apparatus according to the invention.