Abstract: A device for treating a web substrate in a plasma enhanced process. The device includes a treatment station with a vacuum process chamber. A plasma treatment unit is allocated to the treatment station which is designed to form a plasma zone within the process chamber for treating a surface of the web substrate. The device further includes a transporting system for continuously transporting the web substrate through the treatment station with an unwind roller and a rewind roller, wherein the transporting system defines a transporting path of the web substrate through the process chamber. The plasma treatment unit includes an extensive antenna and a radiofrequency generator for exciting the extensive antenna to a resonant frequencies.