In the 1970s, our team at Mitsubishi Rayon (now Mitsubishi Chemical) was developing polypropylene fibers for water and blood filtration. The results were underwhelming — until one researcher examined the fibers under a microscope and discovered thousands of pores lining their hollow walls.
This insight led to a major breakthrough: the creation of hollow-fiber membrane filters. In 1978, they enabled the world’s first artificial lung device and set new standards in wastewater treatment and medical care.
Today, Cleansui continues this legacy, delivering clean, safe water through precision-engineered hollow-fiber membranes.
Hollow-Fiber Membrane
In 1983, inspired by the water quality during a business trip to Mexico, our then-president envisioned a portable water purifier equipped with hollow fiber membrane technology. That vision became reality with the launch of “Mashimizu,” paving the way for home-use purification.
The following year, we introduced our first stationary models — Cleansui S and Cleansui D. Then in 1989, our faucet-mounted “Cleansui Petit” became a nationwide hit, marking a turning point in household water care.
Since then, we’ve continued to expand the Cleansui lineup, delivering clean, safe water through trusted Japanese innovation.
The Birth of Cleansui
Cleansui is trusted by millions for good reason. Our high-performance water purifiers use advanced hollow fiber membrane filters to remove 17 JIS-specified substances and 2 additional contaminants — while preserving the natural minerals in tap water.
Our designs are intuitive and elegant, built for everyday ease. The faucet-mounted model is especially economical: one cartridge purifies the equivalent of 450 two-liter PET bottles.
And with direct-from-manufacturer support — including regular cartridge deliveries and a dedicated call center — you can enjoy clean, safe water with total peace of mind.
Why Cleansui
mitsubishi cleansui
A journey of more than 40 years of continuous innovation and development
"Bringing to you the safe, reliable, tasty water that you deserve" is Mitsubishi Cleansui's number one goal. And we won’t stop until we’ve reached it.
mitsubishi cleansui
Cleansui is a member of the
Mitsubishi Chemical Holdings Group
Mitsubishi Cleansui is a part of Mitsubishi Chemical Holdings one of Japan's oldest and most influential corporations. We provide a wide array of products to ensure clean and natural minerals in tap water.
1970
Mitsubishi Rayon, the forerunner of Mitsubishi Chemical Cleansui, conducted research on polyethylene fiber for filtering water and blood.
1974
Successfully researched and developed hollow fiber membrane, laying the foundation for subsequent products.
1978
Production of artificial lungs, continue to research hollow fiber membrane in water treatments.
1983
Introduced the first water purifier using hollow fiber membrane technology in Japan.
1989
Success with the first water purifier in the form of a faucet - Cleansui Petit."
1990
Introduced the first undersink water purifier, featuring an elegant and sophisticated design.
2002
Mitsubishi Cleansui introduced the first commercial water purifier.
2003
Introduced the first pitcher water purifiers
2018
In 2018, we received the Red Dot Award in Product Design for the Cleansui Shigaraki JP100-C water purifier. This purifier was the first product from the project “Cleansui Knows Japanese Crafts,” a collaboration with skilled craftsmen who followed Japanese traditions.
2020
In 2020, we received our second Red Dot Award in Product Design for the faucet-mounted water filter “Cleansui CSP901,” which was designed by award winning product designer Fumie Shibata.