Abstract: The present invention relates to a fresh water generation method including: feeding raw water or pretreated water thereof as feed water into a semipermeable membrane module in a pressurized state using a booster pump, thereby separating the feed water into a concentrate and a permeate having a low concentration, in which a scale inhibitor having a reducing function is dosed intermittently or continuously upstream from the semipermeable membrane module, thereby inhibiting scale generation and maintaining an oxidation-reduction potential of at least either the feed water or the concentrate to a threshold value or lower.