A hydroponic cultivation apparatus comprises: at least cultivation containers 30A, 30B for growing the plants 100； a plurality of plant supporting portions 7A,7B to support the plants 100； a plurality of nutrient solution supplying portions 3A,3B to supply nutrient solutions； a plurality of first switching valves 4A,4B； a plurality of nutrient solution discharging portions 5A, 5B to discharge the nutrient solutions； a plurality of second switching valves 6A,6B； a plurality of pH value detecting portions 8A,8B to detect pH values of the nutrient solutions 110； a receptacle portion 20 to store the nutrient solutions discharged from the plurality of nutrient discharging portions 5A,5B； nutrient solution circulating portions 2A,2B to send the nutrient solutions from the receptacle portion 20； and a controlling portion to control opening and closing operations of the first switching valves 4A,4B and the second switching valves 6A,6B based on the pH values detected by the pH value detecting portions 8A,8B.
