A device for generating a sterilizing gas includes a methanol gas generation device (11) for vaporizing methanol to generate a methanol gas, a tubular part (12) and a catalyst section (13). The tubular section (12) is arranged on top of the methanol gas generation device (11) to provide a flow path for upwardly directing the methanol gas generated by the methanol gas generation device by natural convection. The tubular section also operates to mix the methanol gas with a predetermined proportion of air. The catalyst section (13) is arranged on top of the tubular section (12) for turning the methanol gas mixed with the air at the predetermined proportion in the tubular section (12) into radicals by a catalyzed reaction. The catalyst section (13) is formed by a turn-into-radical reaction catalyst layer (30) obtained on forming a thin metal sheet (35a) to a honeycomb structure.
