Direct oxidation fuel cell

A direct oxidation fuel cell comprising at least:

• one unit cell, the unit cell including:
• a membrane electrode assembly comprising an anode, a cathode, and an electrolyte membrane sandwiched between the anode and the cathode;
• an anode-side separator being in contact with the anode and having a fuel flow channel for supplying a fuel to the anode;
• and
• a cathode-side separator being in contact with the cathode and having an oxidant flow channel for supplying an oxidant to the cathode,
• wherein the cathode includes a cathode catalyst layer in contact with the electrolyte membrane, and a cathode diffusion layer in contact with the cathode-side separator,
• the cathode catalyst layer includes a cathode catalyst and a polymer electrolyte, and
• the amount of the polymer electrolyte contained in a portion of the cathode catalyst layer facing an upstream portion of the fuel flow channel is smaller than that contained in a portion of the cathode catalyst layer facing a downstream portion of the fuel flow channel.