NOVELTY - The microbial fuel cell has a cylinder (1), a cathode (2), an anode (3), rubber rings (4,7), anode cover plate (5), cathode cover plate (6), anode conductor (8) and cathode conductor (9), and is opened at one end and closed at other end. The apertures of rings (4,7) are same. The anode conductor led out by anode and cathode conductor led out by cathode are connected with external circuits. The space between anode and cathode is 1 cm or more. The cylinder has sampling opening (10) at top and water outlet (11) at bottom.    USE - Microbial fuel cell is used for treating brewery wastewater (claimed).    ADVANTAGE - The microbial fuel cell simply, efficiently and economically enables treatment of wastewater.    DETAILED DESCRIPTION - The microbial fuel cell has a cylinder (1), a cathode (2), an anode (3), rubber rings (4,7), anode cover plate (5), cathode cover plate (6), anode conductor (8) and cathode conductor (9), and is opened at one end and closed at other end. The inner sides of ends of cylinder are provided with grooves having anode and ring (7) at closed end. The closed end of cylinder is sealed by anode cover plate, and ring (7) is provided between anode and anode cover plate. The groove at opening end of cylinder has cathode and ring (4). The opening end of cylinder is sealed by cathode cover plate, and ring (4) is provided between cathode and cathode cover plate. The apertures of rings (4,7) are same. The anode conductor led out by anode and cathode conductor led out by cathode are connected with external circuits. The space between anode and cathode is 1 cm or more. The cylinder has sampling opening (10) at top and water outlet (11) at bottom. A combustion chamber (12) is formed in cathode, anode or cylinder. The anode is made of carbon fabric, carbon paper, glassy carbon, foamed nickel, carbon fiber, carbon nanotube, hydrogen storage alloy, graphite particles and graphite felt. The cathode is made of carbon fabric, carbon paper and graphite. Cathode is contacted with water-proof layer containing polytetrafluoroethylene and/or polyurethane.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of microbial fuel cell.    Cylinder (1)    Cathode (2)    Anode (3)    Rubber rings (4,7)    Anode cover plate (5)    Cathode cover plate (6)    Anode conductor (8)    Cathode conductor (9)    Sampling opening (10)    Water outlet (11)    Combustion chamber (12)