Abstract: A crusher with rotary crusher plates and a vertical main axis has plates (1,2) disposed one above the other and spaced apart to form between the plates an annular slot (4) having radial, outwardly converging crushing surfaces (1', 2'). Said plates are rotatable about axes (A,B) which are non-parallel; the lower plate (2) is driven and the upper plate (1) is provided with a central feed opening (3) with a feed funnel (5) projecting downwardly into the opening. During operation, the lower plate (2) is arranged to execute a simultaneous gyrating movement in an opposite direction in relation to its direction of rotation, the number of revolutions per minute of the gyrating movement being substantially higher than the number of revolutions per minute of the lower plate (2) about its axis of rotation (B). The crushing surface (2') of the lower plate (2) has a central, cone-shaped section (2") which projects upwardly into the central feed opening (3) of the upper plate (1).