Abstract: The invention relates to a microbial fuel cell, which comprises a cell reactor, a cathode arranged on a cathode side of the cell reactor, and an anode arranged on an anode side of the cell reactor. The cathode and anode are connected with each other through an external circuit. Further the cell reactor comprises a proton permeable membrane, which is arranged between the anode and cathode, and which divides the cell reactor into the anode side and the cathode side. The membrane comprises a membrane core having a pore size of ?10 nm and/or divalent rejection ?50% and a hydrophilic polymeric surface layer on at least one side of the membrane core and attached permanently to the membrane core. The invention relates also to the use of the microbial fuel cell.