It is possible to change the threshold of the irrigation volume or the irrigation volume itself according to the past drainage volume, to control the irrigation volume more finely and to maintain the drainage volume at the target drainage rate. A hydroponic cultivation apparatus and a hydroponic cultivation control program are provided. The hydroponic cultivation apparatus and the hydroponic cultivation control program calculate a moving average absorption amount and a moving average irrigation amount for the past several days by moving average processing, and based on these moving average values, the irrigation amount Varying threshold and irrigation time. Thereby, finer control of the irrigation amount is possible, and the irrigation amount can be controlled so as to approach the target drainage rate. Further, by using the moving average value of the data for the past several days, it is possible to reduce the influence of the fluctuation of the absorption amount due to the weather or the like. [Selection] Figure 2
