An apparatus for sharpening a beet knife has a plurality of roof-shaped blades next to each other on a knife body has a centering device carrying a centering piece and movable in a Y-direction, a milling device with a mechanically rotatable side miller with a roof-like milling edge movable in the Y-direction toward and away from the centering device, and a guide extending in an X-direction substantially perpendicular to the Y-direction. A grab shiftable in the X-direction on the guide is designed to hold the knife to be sharpened, and respective drives are connected to the centering and milling devices for moving same toward and away from each other in the Y-direction and to the grab for moving same along the guide in the X-direction.
