Abstract: In a method for producing fresh water using solar energy, the method involving the use of an installation comprising a structure oriented toward the sun and permeable to solar radiation, forming a greenhouse including a preheating and reheating chamber and an evaporation chamber into which water containing impurities is introduced to be evaporated by the indirect influence of the solar radiation in the air trapped under the structure, the air being conveyed to a temperature exchanger such that the vapors carried thereby will be condensed and collected, the improvement comprising evaporation of the water containing impurities on mounds of capillary material scattered and distributed over the entire span of the evaporation chamber.