Abstract: An apparatus for continuous liquid-solid separation has suction boxes which respectively have a suction hole on a rear surface and a perforated surface at a front surface and said suction boxes being connected in series to form a conveyor and said suction holes being connected to a suction trough so as to give the sucking condition of the suction boxes in the zone of the suction trough wherein a filter cloth is contacted with the perforated surfaces of the suction boxes and is held by side plates which can be closed and opened at both sides of the suction boxes and the filter cloth and the suction boxes are moved at the synchronized velocity under suction.