NOVELTY - A desulfurizer (1) has a desulfurization catalyst (11), a sulfur-containing liquid fuel inlet to introduce sulfur-containing liquid fuel, a desulfurized liquid fuel discharge port to discharge desulfurized liquid fuel, a container (a), a combustion catalyst (21), an oxygen-containing gas introduction port (23) to introduce oxygen-containing gas, a nature inlet of burning material and a discharge port, and a container (b) to accommodate combustion catalyst in the position interposed into the oxygen-containing gas introduction port and nature inlet of burning material.    USE - Desulfurizer is used for fuel cell electric power generation system (claimed).    ADVANTAGE - The fuel cell electric power generation system formed using the desulfurizer de-sulfurizes the liquid fuel, and has excellent electric power generation efficiency.    DETAILED DESCRIPTION - A desulfurizer has a desulfurization catalyst, a sulfur-containing liquid fuel inlet to introduce sulfur-containing liquid fuel, a desulfurized liquid fuel discharge port to discharge desulfurized liquid fuel obtained by contacting sulfur-containing liquid fuel and desulfurization catalyst, a container (a) which accommodates desulfurization catalyst in a position interposed into the sulfur-containing liquid fuel inlet and desulfurized liquid fuel discharge port, a combustion catalyst, an oxygen-containing gas introduction port to introduce oxygen-containing gas, a nature inlet of burning material and a discharge port, and a container (b) to accommodate combustion catalyst in the position interposed into the oxygen-containing gas introduction port and nature inlet of burning material, and discharge port. The container is provided in heatable position. An INDEPENDENT CLAIM is included for fuel cell electric power generation system, which has polymer electrolyte fuel cell electric power generating apparatus to discharge oxygen-containing gas comprising oxygen, desulfurizer which de-sulfurizes sulfur-containing liquid fuel supplied to polymer electrolyte fuel cell electric power generating apparatus, and a modifier to generate hydrogen-rich gas by steam-reforming reaction using de-sulfurized liquid fuel discharged from the desulfurizer, and is supplied to the polymer electrolyte fuel cell electric power generating apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows the cross-sectional view of the desulfurizer.    Desulfurizer (1)    Desulfurization catalyst (11)    Combustion catalyst (21)    Oxygen-containing gas introduction port (23)    Combustion exhaust gas discharge port (25)