A treatment device (1) and a treatment method for a web (2) of endless material, in particular of a textile fiber material, preferably a non-woven fabric are provided. The treatment device (1) includes a treatment chamber (14) in which the moving web (2) is treated with a flowing gas, in particular air, an inlet (10) and an outlet (11) for the web (2), and a plurality of chamber regions (20-24). The plurality of chamber regions (20-24) are stationarily arranged on top and next to each other. The web (2) runs through the plurality of chamber regions (20-24). In the chamber regions (20-24), the gas, in particular the air, flows against and through the web (2) from one side.