We can produce ultra-pure water, pyrogen-free water, and bacteria-free water for high-demanding applications. This can be achieved through the combination of different water treatment processes such as Reverse Osmosis, Ultrafiltration, Electro-Deionization, and Ultra-violet Sterilization. This system is designed for low energy consumption, easy construction, simple operation, and less maintenance requirement. Ultra-pure water has been applied to the manufacturing of IC chips, opto-electric parts, and pharmaceutical products.