It is to provide an antioxidant excellent in antioxidative potential and having high safety is provided. Also, it is to provide an antioxidant in which problems of unpleasant smell and taste are avoided and its preparation method is not so complex. Further, it is to provide an antioxidant which can exert its effect by a simple operation when exertion of the antioxidative potential is desired. It relates to a double preparation type antioxidant, which comprises a mixture A comprising a polyphenol and a mixture B comprising an alkali agent. In particular, two antioxidant component-storing containers are mutually integrally molded and combined, and a mixture A comprising a polyphenol is stored in one of the antioxidant component-storing containers and a mixture B comprising an alkali agent is stored in the other antioxidant component storing container.