PROBLEM TO BE SOLVED: To provide an apparatus and a method for preparing an aqueous hypochlorous acid solution without using any acid and substantially without producing any chlorine gas.SOLUTION: The method for preparing weakly acidic hypochlorous acid comprises a step of treating a hypochlorous acid solution with a weakly acidic ion exchanger. The apparatus for preparing the weakly acidic hypochlorous acid is equipped with the weakly acidic ion exchanger. A container for preparing the weakly acidic hypochlorous acid comprises a weakly acidic ion exchanger that exerts a buffer action at a pH at which calcium hypochlorite and chlorine gas are produced or higher. The weakly acidic hypochlorous acid is obtained by the method.本發明之目的係提供一種用以製造次氯酸(hypochlorous acid)水溶液的裝置及方法，其不使用酸，且實質上不會產生氯氣。本發明係提供一種弱酸性次氯酸之製造方法，其係包含以弱酸性離子交換體處理次氯酸鹽溶液的步驟之製造方法。又，提供一種具備弱酸性離子交換體的弱酸性次氯酸之製造裝置。再者，提供用以製造弱酸性次氯酸之容器，其包含次氯酸鈣、及於氯氣產生的pH值以上具有緩衝作用的弱酸性離子交換體。此外，提供由上述方法所獲得的弱酸性次氯酸。
