The present invention relates to a curtain coater and a curtain-coating method for coating a moving web (2) of paper or board. The curtain coater comprises an applicator nozzle (1) located above the web (2) to be coated so as to apply the coating mix therefrom to the surface of the web (2) in the form of a continuous curtain extending uniformly over the cross-machine width of the web (2). The boundary air layer traveling on the surface of the web (2) is removed by a doctoring means (3) which is located upstream in the travel direction of the web (2) in front of the impingement point of the coating mix curtain on the surface of the web (2) and is further located on the same side of the web (2) as the applicator nozzle (1).