NOVELTY - An inorganic chemical substance composition contains alumina, silica-alumina, silica and/or zirconia, and/or ruthenium as active-metal species, ruthenium-cobalt alloy, ruthenium-molybdenum alloy, or ruthenium-molybdenum-cobalt alloy supported to support containing element chosen from alkali metal, alkaline-earth metal, metal of group III, lanthanoid-type metal, and titanium (0.7-27 wt.%) based on metal conversion total weight standard. The addition amount of active-metal species is 4-21 wt.% based on metal conversion total weight standard.    USE - Inorganic chemical substance composition is used for manufacturing fuel gas (claimed) e.g. reducing gas, town gas, gas for petroleum refining, biomass-derived glycerol, gas supply for environmentally-friendly fuel, and fuel for fuel cell and hydrogen fueled car.    ADVANTAGE - The fuel gas is efficiently manufactured, using the inorganic chemical substance composition.    DETAILED DESCRIPTION - An inorganic chemical substance composition contains alumina, silica-alumina, silica and/or zirconia, and/or ruthenium as active-metal species, ruthenium-cobalt alloy, ruthenium-molybdenum alloy, or ruthenium-molybdenum-cobalt alloy supported to support containing element chosen from alkali metal, alkaline-earth metal, metal of group III, lanthanoid-type metal, and titanium (0.7-27 wt.%) based on metal conversion total weight standard. The addition amount of active-metal species is 4-21 wt.% based on metal conversion total weight standard. The weight ratio of ruthenium and cobalt in ruthenium-cobalt alloy is 0.3-9.5. The molar ratio of ruthenium and cobalt in ruthenium-cobalt alloy is 0.2-3.5. The content of ruthenium is 3.5 wt.% or more based on metal conversion total weight standard, and remainder of cobalt and molybdenum in the ruthenium-molybdenum-cobalt alloy. An INDEPENDENT CLAIM is included for manufacture of fuel gas containing hydrogen or methane from non-petroleum raw material, which involves supplying and processing inorganic chemical substance composition at 400-800 degrees C or 380-550 degrees C.