Hydrogen energy system is expected as a key technology for the sustainable developing society. The surface grating technologies enable to control the thermal radiation spectrum. We are applying this technique to promote the chemical reaction to produce hydrogen. In this study, we research to make hydrogen production promoted in the process of methane steam reforming by spectrally resonant thermal radiation. The thermal radiation spectrum is adjusted to vibrational absorption bands of methane and water molecules by making a two-dimensional surface grating with microcavities on the radiative surface. By matching the peak of thermal radiation to the absorption bands of gases, it is clearly observed that the chemical reaction is promoted by the optical excitation of vibrational energy levels of molecules.