In a method of cleaning and sterilizing an ultrapure water manufacturing system including an ultrapure water manufacturing apparatus, a point of use of ultrapure water, and an ultrapure water channel connecting the ultrapure water manufacturing apparatus and the point of use, a cleaning and sterilizing process including an alkali cleaning step for cleaning at least part of the inside of the system with alkaline solution and a sterilizing step for sterilizing the system with sterile water after the alkali cleaning is treated twice or more. By treating the cleaning and sterilizing process twice or more, metals, organic substances, particles, and bacteria inside the ultrapure water manufacturing system can be highly efficiently removed, and thereby ultrapure water satisfying required water quality can be produced within a short period of time after the cleaning and sterilizing.本發明係提供一種超純水製造裝置、超純水使用點、及由連結該超純水製造裝置與該使用點之超純水之通路所成之洗淨及殺菌超純水製造系統方法中,進行2次以上之以鹼性溶液洗淨系內之至少一部份之鹼洗淨步驟與於該鹼洗淨後,以殺菌水進行殺菌之殺菌步驟之洗淨殺菌步驟者為其特徵之超純水製造系統之洗淨殺菌方法。藉由進行2次以上之洗淨殺菌步驟,可高效率去除超純水製造系統系內之金屬、有機物、微粒子、生菌,洗淨殺菌後,可於短期間內,製造出滿足所要求水質之超純水。5‧‧‧一次純水製造裝置3b‧‧‧通路4‧‧‧使用點3a‧‧‧通路1‧‧‧超純水製造系統25a‧‧‧旁通配管26a‧‧‧旁通配管27a‧‧‧旁通配管2‧‧‧超純水製造裝置21‧‧‧儲存槽22‧‧‧泵23‧‧‧熱交換器24‧‧‧低壓紫外線氧化裝置25‧‧‧脫氣裝置26‧‧‧離子交換裝置27‧‧‧超過濾膜(UF)裝置
