The harvested material is threshed by a drum (3) and fine material falls to a vibrating conveyor (11) driven in a direction P1, while the remainder enters a separation screw (7) when further material falls to a vibrating plate (10) as the straw progresses to fall out (13). The fine material joins the first filtered material on the conveyor (11) and is then blown by a fan (14) over a filter (15) to deliver the fine sorted result.