A filter device for cleaning particulate contaminants from a fluid flow, includes a plurality of filter elements (34, 60) accommodated in filter chambers (12, 14, 32) as components of a joint filter housing (10) and grouped around a backwash device (20) having a piston accumulator (56) for receiving a backwash fluid. In the storage housing (64) of the piston accumulator, a piston (57) is guided in a longitudinally movable manner, is controlled by a pressure medium, and passes on the backwash fluid stored in the storage housing (64) on to at least one filter element (60) to be backwashed for cleaning purposes via a backwash device (20). The backwash device also discharges the backwash fluid from the filter device. A specific filter element as a bypass filter element (34) is selected from the plurality of filter elements (34, 60), and exclusively removes particles after a changeover device (18) has been actuated, while the other filter elements (60) are excluded from this removal process.