NOVELTY - A reformation unit (300) has a water vapor generation unit to generate water vapor from water supplied, a reformed-gas generation unit to mix water vapor and a source gas, and to generate a reformed gas, a carbon monoxide removal unit which is filled with a catalyst to remove carbon monoxide in the reformed gas, a flowing water path to supply water after the water is circulationable and heat-exchanging inside with the catalyst of carbon monoxide removal unit to the water vapor generation unit, and a bypass path to supply water to the water vapor generation unit.    USE - Reformation unit is used for fuel cell system (claimed) using hydrocarbon raw material such as kerosene or liquefied petroleum gas.    ADVANTAGE - The fuel cell system formed using the reformation unit generates hydrogen efficiently.    DETAILED DESCRIPTION - A reformation unit has a water vapor generation unit to generate water vapor from water supplied, a reformed-gas generation unit to mix water vapor and a source gas, and to generate a reformed gas, a carbon monoxide removal unit which is filled with a catalyst to remove carbon monoxide in the reformed gas, a flowing water path to supply water after the water is circulationable and heat-exchanging inside with the catalyst of carbon monoxide removal unit to the water vapor generation unit, and a bypass path to supply water to the water vapor generation unit. The catalyst of carbon monoxide removal unit supplies water to the flowing water path, when the temperature is higher than the dew point of water vapor. The carbon monoxide removal unit has a water supply unit to supply water to the bypass path, when the temperature is below dew point of the water vapor. An INDEPENDENT CLAIM is included for fuel cell system.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of the reformation unit. (Drawing includes non-English language text)    Heating unit (151)    Reformation unit (300)    Modifier (620)    Carbon monoxide modifying device (820)    Carbon monoxide selective-oxidation device (830)