PROBLEM TO BE SOLVED: To provide a structure of a plant hydroponic apparatus capable of efficient and automatic two-dimensional spacing, and a hydroponic method.SOLUTION: In the hydroponic apparatus, a sowing unit feeding area is disposed at the center, and a harvesting area is disposed in the outer periphery. The sowing units are gradually moved in the outer peripheral direction by a feeding mechanism while rotationally transferring the sowing units from the sowing unit feeding area to the harvesting area, and grown plants are harvested in the harvesting area.