PROBLEM TO BE SOLVED: To provide a hydroponic culture apparatus having a nutrient solution tank that can be realized with a simple configuration to obtain an optimum nutrient solution level in each cultivation process if there is a difference in planting time.SOLUTION: A nutrient solution tank 3 is used in a hydroponic apparatus for cultivating plants 7 planted on a cultivation tray 5 in which the plurality of plants 7 is planted by circulating a nutrient solution 9. The nutrient solution tank 3 comprises: a main body 3a in which a nutrient solution storage space is formed and on which the plurality of cultivation trays 5 can be mounted movably in the longitudinal direction； a water supply device 3f disposed at one end in the longitudinal direction； and a drain outlet 3g at the other end in the longitudinal direction. The main body 3a includes one or more partition plates 6 that divide the nutrient solution storage space into a plurality of areas 10, 11, 12 having different depths H1, H2, H3 of storable nutrient solution 9 in the longitudinal direction in such a way that they can be mounted and disposed freely.SELECTED DRAWING: Figure 4【課題】定植時期に差があっても、それぞれの栽培過程において最適な養液水位になるよう、簡単な構成で実現することが出来る養液槽を持つ水耕栽培装置を提供する。【解決手段】養液９を流通させることで、複数の植物７が植設された栽培トレイ５上に植設された植物７を栽培する水耕栽培装置に使用される養液槽３において、養液槽３は、内部に養液貯留空間が形成され、複数の栽培トレイ５をその長手方向に移動自在に搭載することの出来る本体３ａを有し、長手方向の一端に、給水装置３ｆが設けられ、他端には排水口３ｇが設けられ、本体３ａには、一つ以上の仕切り板６が、養液貯留空間を長手方向に、貯留可能な養液９の深さＨ１，Ｈ２、Ｈ３が異なる複数のエリア１０，１１，１２に区分する形で装着配置自在に設けられている。【選択図】図４
