A sieve (166) for a combine harvester (100) cleaning device (146) comprises a frame (10), in which a plurality of similar transversely extending plates (12) are mounted for angular adjustment about respective transverse axes defined by axles (20) that are equally spaced from each other in the longitudinal direction. The plates (12) are angled upwards and rearwards, with adjacent ones of the plates having forward sections of one overlapping rearward sections of the other. The axles (20) include cranks 14 that define adjusting elements, which are received for interacting with slots (16) provided in a longitudinally extending adjusting rod (18) that can be adjusted in its position in the longitudinal direction of the sieve (166), relative to the frame (10), so as to be able to adjust the angles of the plates (12) around their axles (20). The slots (16) are shaped and arranged on the adjusting rod (16) in such a way that at least one plate (12) has an angle different from another plate (12).
