The microporous hollow fiber membrane is a sophisticated filter developed by Mitsubishi Chemical's macromolecular chemical technology in 1984 for the first time in the world. Mitsubishi chemical's hollow fiber membrane, which can remove the minute particles as 0.1 micrometer in tap water, has been appraised as a highly precise filtration system and widely applied to water purifying plant, producing of high-quality medical-use water and many areas of water purification.