A device for the direct or indirect application of liquid or pasty application medium by means of an applicator unit to a material web, in particular of paper or board, comprises a device upstream of the applicator unit in the running direction of the substrate in order to attenuate the air boundary layer carried along by the substrate. The device comprises highly porous adsorbent particles, and the adsorbent particles are immobilized by an inert matrix. A seat is supported by the frame and a tray extends across and is spaced forward from the seat assembly.