HYDROGEN PRODUCTION APPARATUS AND FUEL CELL SYSTEM

A hydrogen production apparatus 1 includes a preferential oxidation unit 8 that preferentially oxidizes carbon monoxide in a reformed gas containing hydrogen, a vaporization flow path 33 that passes water to generate steam, and a gas flow path 34 through which the reformed gas passes. The gas flow path 34 is arranged between the preferential oxidation unit 8 and the vaporization flow path 33. The reformed gas passes through the gas flow path 34 and thereafter flows into the preferential oxidation unit 8.