<p>Disclosed is a water processing device (10) comprised of a reverse osmosis membrane (28), a cylindrical container (24) with the reverse osmosis membrane (28) housed therein, and a supply pipe (42) for the water processing device connected to outer surface of the container (24) such that it is tangential to the inner surface of the container (24). This embodiment allows the whole face of the reverse osmosis membrane (28) to be efficiently exposed to the water for treatment, which improves treatment performance of the reverse osmosis membrane (28).</p>
