Patent ID: 7892665

Claim:
A direct methanol fuel cell system comprising: (A) (i) a fuel cell unit including a proton conductive polymer electrolyte membrane held between an anode and a cathode, a passage for supplying a liquid fuel to the anode, and a passage for supplying an oxidizer gas to the cathode; or (ii) a fuel cell stack obtained by stacking a plurality of fuel cell units, wherein each of the fuel cell units is the fuel cell unit; and (B) a fuel cartridge storing the liquid fuel to be supplied to the anode, wherein the liquid fuel contains methanol and water and has an electrical resistance of 5×10 5 Ω·cm to 1×10 7 ω·cm at 25° C., and wherein a material for all members in the fuel cartridge to be brought into contact with the liquid fuel is made of only a resin containing no plasticizer, or glass.