Freshwater production apparatus and method for producing freshwater

The present invention provides a freshwater production apparatus for pre-treating raw water with a pre-treatment device (5) such as a pre-treatment membrane module provided with a microfiltration membrane and/or an ultrafiltration membrane or a sand filtration device, and supplying the resulting pre-treatment water directly to a reverse osmosis membrane device (10) without passing through an intermediate tank, wherein the freshwater production apparatus makes it possible to backwash the pre-treatment device (5) without impairing the stable operation of the reverse osmosis membrane device (10). The present invention also provides a method for producing freshwater whereby freshwater is produced from raw water by the freshwater production apparatus.