Abstract: A settling machine for upgrading materials, particularly for upgrading coal, comprises at least one settling chamber filled with water and having a jig screen covering at least a part of the chamber arranged at the water level. The chamber is also connected laterally of the jig screen to a plurality of different pressure sources and the connections are such that pressures may be superimposed on the liquid of the chamber to cause a pulsation thereof for the separation of the material contained on the jig screen. With the method of the invention, the pressure is connected via control lines having control valves which may be adjusted to get a number of settling strokes per minute by pressure surges which may be set to the range of between 20 to 50 settling strokes per minute for one of the control valves, and for the other control valve, may be arranged between 150 and 250 settling strokes per minute.