PURPOSE: To maintain a filtering device easily by forming a supplying chamber and a discharging one of a liquid to be treated at one side end of a filtering vessel, and connecting the chambers by a U-shaped porous tube.

CONSTITUTION: The end parts of porous tubes 10, constituting a filter medium, are joined to a tube plate 88 by welding. And the ends of U-shaped tube 102 are respectively joined by welding to the bottom ends of tubes 10 so that the tube 10 fixed to a supplying chamber 94 and the tube 10 fixed to a discharging chamber 96 are communicated with each other. In a case of disassembling a filtering device 82 constituted in such a manner, a joining part between a vessel 84 and an end plate part 90 is released, and the part 90 is taken out by lifting it with the aid of a crane, etc. after discharging a filtrate in the vessel 84 by a drain pipe 86. Thereafter, a hanger is attached to the plate 88 to lift it by the crane. Then the filter medium 98 consisting of the tubes 10 is lifted together with the plate 88.