Abstract: The aim of the invention is to coat running material webs (1). According to prior art, the coating material is applied to the material web (1) by means of curtain coaters. Said coating material is discharged from a slit nozzle (2) and passes through a free-falling curtain (3). The edges of the curtain (3) are separated by means of separating elements (9, 10) before the fall into the material web (1) for adjusting the coating width. According to the invention, a smaller curtain is produced on each edge by means of a first outer separating element (10). Said curtain is adjusted to the desired coating width by means of a second, inner separating element (9). In a preferred embodiment, an inner separating element (9) is used which contains a vertical channel in the interior thereof. Said channel is open on the separating edge. A water supply (24) flows into said channel.