Water scarcity will become a serious problem due to climate change and population growth. In this research, we have introduced a water-saving mist cultivation system, comprising a sealed container and an ultrasonic mist generator. One of the features of this system is the intermittent supply of nutrient solution in mist form. We confirmed that optimization of water supply frequency enabled operation with about 70% less water, 65% less CO2 emission, and 84% less nutrients compared to conventional hydroponics without scarifying the yield of lettuce. In addition, we found that the sugar content in tomato could be increased by controlling the watering frequency and time.