To provide a fuel cell capable of discharging a gas produced at a fuel electrode to the outside and its manufacturing method.

A part of the electrolyte membrane of the cell part of the fuel cell is thinned, a hole is made in a conductive membrane formed on the electrolyte membrane by coming into contact with it to serve as an air electrode, and a gas produced at the fuel electrode can be discharged from this part. Thereby, the reacting area of the fuel electrode has no possibility of decreasing due to accumulation of the gas, and high output power can be generated. In addition, since the air electrode and the fuel electrode are integrally formed on the front surface and back surface of the sheet of each three layer structure, and the electrodes are not required to be connected each other. Therefore, the manufacturing cost of the cell part is not increased and reliability is not lowered.