A hydroponic cultivation device (200) which comprises: a shading cultivation tank (20) which houses therein the underground part (7) of a perennial plant (3) and constitutes an underground space (70) in which the underground part (7) grows; a shading partition part (23) which is disposed so as to cover the upper opening of the cultivation tank (20) around the perennial plant (3), encloses together with the cultivation tank (20) the underground part (7), and separates the underground space (70) from an above-ground space (80) in which the above-ground part (6) of the perennial plant (3) grows; a holder part (90) which holds the underground part (7) so as to prevent the exposure of a new sprout (8) of the perennial plant (3) to the above-ground space (80); and a spray part (26) which sprays water or a nutrient solution in the shaded underground space (70) so as to keep the new sprout (8) in a moist state.
