PROBLEM TO BE SOLVED: To provide a water treatment device for sterilization purification capable of achieving a surer fluid treatment and compactification of a product by allowing an ozonizer and a reaction vessel to have a separate structure.SOLUTION: A discharge type ozonizer and a reaction vessel having a built-in ultraviolet lamp are allowed to have a separate structure, and ozone water formed by mixing ozone produced by the ozonizer with treatment water is changed into ozone water for treatment by extracting therefrom waste ozone gas from an air separator with a vent valve. In a water treatment device for sterilization purification, the ozone water for treatment is conducted into the reaction vessel.【課題】本発明の目的は、オゾナイザーと反応槽を別体構造とすることでより確実な流体処理と製品のコンパクト化を図った除菌浄化用水処理装置を提供することにある。【解決手段】放電式のオゾナイザーと紫外線ランプを内蔵した反応槽とを別体構造とし、オゾナイザーで生成したオゾンと処理水を混合したオゾン水を空気抜き弁付きエアセパレータにより排オゾンガスを抜いて処理用オゾン水とし、この処理用オゾン水を反応槽に通水する除菌浄化用水処理装置である。【選択図】 図2