Hydrogen can be photocatalytically produced from methane and water by using platinum-loaded semiconductor photocatalysts. Platinum-loaded lanthanum-doped NaTaO3 (Pt/NaTaO3: La) showed higher photocatalytic activity for this reaction than platinum-loaded TiO2 did. The apparent quantum yield of this system employing Pt/NaTaO3:La was estimated to be higher than that of photocatalytic water splitting system employing NiO/NaTaO3:La.