PROBLEM TO BE SOLVED: To provide acidic electrolytic water having bactericidal activity for a long period (for example, 6 months or longer), and to provide a method for producing the same.SOLUTION: Acidic electrolytic water has an effective chlorine concentration of 15 ppm or higher, contains at least one selected from an acid salt of an inorganic acid, disodium dihydrogenpyrophosphate, sodium hexametaphosphate and sodium dihydrogen phosphate, has a pH value of 3.0 or higher and below 7.0, and has the LD 50 value of the acid salt of the inorganic acid of 300 mg or more. In a method for producing acidic electrolytic water, raw material acidic electrolytic water is prepared by electrolysis of chlorine-based electrolyte aqueous solution, and an acid salt of an inorganic acid is added to the raw material acidic electrolytic water having the effective chlorine concentration of 15 ppm or higher.【課題】長期間（例えば６か月以上）にわたって殺菌力を有する酸性電解水およびその製造方法を提供する。【解決手段】酸性電解水は、有効塩素濃度が１５ｐｐｍ以上であり、かつ、無機酸の酸性塩、ピロリン酸二水素二ナトリウム、ヘキサメタリン酸ナトリウム、およびリン酸二水素ナトリウムから選ばれる少なくとも１つを含み、ｐＨ値が３．０以上でありかつ７．０未満であり、無機酸の酸性塩のＬＤ５０の値が３００ｍｇより大きい。塩素系電解質水溶液の電気分解によって前記原料酸性電解水を調整、有効塩素濃度が１５ｐｐｍ以上である原料酸性電解水に無機酸の酸性塩を添加する酸性電解水の製造方法。【選択図】図１
