A hydroponic cultivation apparatus (100) includes: a cultivation chamber underground portion (67) internally including an underground space where a subterranean part (1A) of a plant (1) grows such that the underground space is separated from an above-ground space where an aerial part (1B) of the plant (1) grows; an underground temperature adjuster (2478) which adjusts a temperature of an atmosphere inside the underground space; and a controller (50) which controls the underground temperature adjuster (2478), in which the controller (50) includes a dormancy determination unit which determines whether a time of cultivation of the plant (1) is a dormant period when leaves of the aerial part (1B) wither, and a temperature controller which makes the underground temperature adjuster (2478) adjust the temperature of the atmosphere inside the underground space so as to facilitate germination of the plant (1) in a case where the dormancy determination unit determines that the time of cultivation of the plant (1) is th
