A hydroponic apparatus includes: a cultivation tank inside which a plant is held, and into a lower portion of which a nutrient solution is introduced； a separator that separates a first space where aboveground portions of the plant are positioned and a second space where underground portions of the plant are positioned； an environmental control unit that performs control of adjusting a temperature of the first space to a first temperature in a first period and adjusting the temperature of the first space to a second temperature lower than the first temperature in a second period； and a humidity control unit that performs control to decrease a humidity of the second space when the growing period for the plant shifts from the first period to the second period.
