To provide an apparatus that can gasify a sterilizer containing hydrogen peroxide to produce a gas having a high hydrogen peroxide concentration. The apparatus can stably produce a gas of the sterilizer containing hydrogen peroxide for a long time.A heating surface of a heating body that gasifies the sterilizer is made of chromium. Alternatively, the heating surface of the heating body that gasifies the sterilizer may be made of polytetrafluoroethylene or perfluoroalkoxy fluorocarbon resin, or a chromium plating impregnated with chromium polytetrafluoroethylene or perfluoroalkoxy fluorocarbon resin.