A device for applying a liquid to pasty medium to a moving surface, the moving surface in the case of direct application being the surface of a paper, board or other fibrous web. In the case of indirect application the moving surface being the surface of a transfer element which transfers the application medium to the surface of the fibrous web. The device includes an applicator for applying the medium and a doctor device arranged downstream in the running direction of the moving surface for doctoring off and/or equalizing the medium applied to the moving surface. In order to collect excess medium that has not remained on the moving surface and/or has not reached the latter, a flexible collecting part covering the interspace between applicator and doctor device is provided, which extends transversely with respect to the running direction of the moving surface and parallel to the applicator and the doctor device.