Abstract: A lamella settler (1) comprises a basin (10) with an inlet for liquid to be cleaned and a sludge outlet and with a plurality of outlet openings (12) for cleaned liquid. Each of a plurality of outlet flumes (16)connects to one of the plurality of outlet openings (12). A plurality of lamella plates are (18) attached to adjacent flumes (16). By providing a plurality of transverse beams (14) above the basin (10), wherein the outlet flumes (16) are supported by the beams (14), an improved lamella settler is achieved which is easier to manufacture and assemble and which has improved characteristics.