The present invention has as its object the provision of a processing method that can perform a sterilization process and a deodorization process utilizing ozone with high efficiency, without humidification of a target object.A processing method of the present invention includes obtaining an ozone-containing gas by irradiating an ozone material gas with ozone generation light that does not include light in an ozone decomposition wavelength range and does include light having a wavelength of not more than 200 nm； and exposing a target object to the obtained ozone-containing gas in a low humidity condition having a relative humidity of not more than 55% to process the target object.
