The invention refers to a grinding device and a grinding method for grinding at least one knife. The grinding device comprises a frame (20) with a knives holder (13.1, 13.2) and a grinding unit (30) comprising a grinding head (21), a grinding head holder (3.1, 3.2, 33.1, 33.2), and a grinding head drive (7.1, 7.2). The grinding unit (30) can selectively be placed on the frame (20) or can be disconnected from the frame (20) and can be placed on the cutting assembly with knives to be grinded. In both operating modes the drive (7.1, 7.2) rotates the grinding head (21) and moves the rotating grinding head (21) with respect to the grinding head holder (3.1, 3.2, 33.1, 33.2).
