To provide an ultrapure water production apparatus capable of suppressing a fluctuation of use amount at a use point and fluctuation of a flow rate of ultrapure water to be produced while stably maintaining an extra-high water quality even during maintenance of each device.
An ultrapure water production apparatus sequentially includes a pretreatment system 11, a primary pure water system 12 and a secondary pure water system 13. In the ultrapure water production apparatus, the primary pure water system 12 comprises a plurality of lines each having a pure water system with the same configuration to which water is individually supplied from a water storage pit 2 storing treatment water of the pretreatment system 11 by a pump P and which includes an ion-exchange resin device 103 and a reverse osmosis membrane device 105 and is configured without the water storage pit interposed. While any one line of the lines is stopped, the other treatment lines can be operated.
MATSUI YASUNORI
KOSAKA KENGO
AWANO SHOTARO
