Cross flow filter device comprising a longitudinal first filter element (1) having a first width (w1) and a longitudinal central axis (8), a longitudinal second filter element (2) having a second width (w2) and being longitudinally installed substantially concentrically inside said first filter element (1), a housing (3) surrounding said first filter element (1), said cross flow filter device having respectively a raw material inlet (4), a concentrate outlet (5), and a first filtrate outlet (6) connected to said first filter element (1). The ratio between the second width (w2) and the first width (w1) is 65%, preferably at least 70% and more preferably about 75%.