Patent ID: 7674548

Claim:
A fuel cell comprising a single cell including: a membrane assembly electrode unit comprising a fuel electrode to which an aqueous methanol solution is supplied as a fuel, an air electrode to which an oxidizing gas is supplied, and an electrolyte membrane interposed between the electrodes; a fuel separator and an oxidizing gas separator disposed at both sides of the membrane assembly electrode unit; and seal members respectively disposed between the membrane assembly electrode unit and the fuel separator and between the membrane assembly electrode unit and the oxidizing gas separator, the seal member including a copolymer of a monomer containing a metal element represented by the following formula (I): where R 1 denotes an aromatic functional group; R 2 , R 3 , R 6 and R 7 each denote an aliphatic functional group or a halogen group, which are the same or different; R 4 denotes an aliphatic functional group; R 5 denotes an aromatic functional group; R 8 denotes an aromatic function group; M 1 and M 2 each denote a metal element, which are the same or different; and m and n each denote an integer of 1 or more.