A method for production of vegetables is disclosed by which the content of beneficial ingredients (nutritious ingredients, flavor ingredients, and the like), such as ascorbic acid, sugar, glucosinolates, polyphenol, chlorophyll, etc., is increased, while nitrate ion content is decreased, and, in the case of anthocyanin producing vegetables, anthocyanin production is enhanced. The method for production is characterized in that the vegetables, after having grown and immediately before harvesting, are subjected, to conditioned cultivation for not less than one day in which the vegetables are hydroponically cultivated with water instead of a nutrient solution and with photoperiod set at not less than 17 hours.