The present invention is intended to provide an apparatus and a method for producing an aqueous solution of hypochlorous acid without using acid and without generating chlorine gas substantially. The present invention provides a method for producing weakly acidic hypochlorous acid, comprising a step of treating hypochlorite solution with a weakly acidic ion exchanger. The present invention also provides an apparatus for producing weakly acidic hypochlorous acid, comprising a weakly acidic ion exchanger. Furthermore, the present invention provides a container for producing weakly acidic hypochlorous acid, comprising a calcium hypochlorite and a weakly acidic ion exchanger having buffer action at the pH value more than that of generating chlorine gas. Furthermore, the present invention provides weakly acidic hypochlorous acid produced by the above method.
