A fuel cell comprises a cell unit in which a plurality of single cells are laminated, each of which has a membrane type electrode unit including 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 fuel electrode and the air electrode, and a fuel absorbing member disposed around the cell unit, the fuel absorbing member being composed of a polymer represented by the following formula (I) ##STR00001## where R.sup.1 denotes a cationic aromatic functional group, R.sup.2 denotes an anion, and n is an integer of 2 or more.