Abstract: When drying a web-formed material, the web-formed material is passed, in contact with a gas-permeable dryer screen, through a drying plant. One or more fans blow hot process air against, and through, the web-formed material in order to dry it. A chamber, surrounding the fan or the fans, has a limiting surface that is essentially parallel to the surface of the web-formed material. This limiting surface has an opening that extends essentially across the whole width of the web-formed material. A distributing member, in the form of an arcuate perforated, sheet-formed element, placed outside the chamber, covers the opening completely. With the distributing member a first flow of process air is divided into a large number of jets, distributed over essentially the whole of the angular area that faces the web-formed material.