Fresh Water Generating Apparatus and Fresh Water Generating Method

An object is to provide a fresh water generating apparatus that is capable of efficiently and stably producing fresh water. Provided is a fresh water generating apparatus equipped with a seawater-treating reverse osmosis membrane device that produces fresh water from seawater by a reverse osmosis membrane, including a mixing section that mixes wastewater as dilution water with seawater to produce mixed water, and a first seawater-treating reverse osmosis membrane device that acts as the seawater-treating reverse osmosis membrane device to filter the mixed water, in which the apparatus is configured so that used water that is wastewater resulting from the use of the produced fresh water as service water is mixed as dilution water with seawater at the mixing section.