PROBLEM TO BE SOLVED: To provide a hydroponic device installed with cultivation containers in a multistage form, and allowing to lessen the water supply amount per time with a pump while securing a necessary water amount to supply to each cultivation container.SOLUTION: This hydroponic device arranged with cultivation containers 3 in a vertical multistage form includes using for each of the cultivation containers 3, two kinds of a mountain fold-like container 31 inclined downward only by a small angle from a length direction central part to each end part, and a valley fold-like container 32 inclined downward only by a small angle in a length direction from each end part to a central part, and arranging sequentially alternatively the mountain fold-like containers 31 and the valley fold-like containers 32 in a multistage form. Furthermore, the device includes supplying nutritious liquid in a nutritious liquid tank 20 to the highest position of the highest stage container with a nutritious liquid circulating device 2, letting nutritious liquid naturally flow from the lowest position of the upper stage container to the highest position of the lower stage container in the containers of each stage vertically adjacent to each other, and letting nutritious liquid naturally flow from the lowest position of the lowest stage container into the nutritious liquid tank so as to circulate nutritious liquid between the nutritious liquid tank and each of the cultivation containers.【課題】栽培容器を多段状に設置した水耕栽培装置において、各栽培容器に供給する必要水量を確保しつつポンプによる時間当たりの供給水量を少なくし得るようにする。【解決手段】栽培容器３を上下多段状に配置した水耕栽培装置において、各栽培容器３は、長さ方向中央部から各端部に向けて若干角度だけ下降傾斜させた山折り状容器３１と、長さ方向各端部から中央部に向けて若干角度だけ下降傾斜させた谷折り状容器３２の２種類を使用して、山折り状容器３１と谷折り状容器３２とを順次交互に多段状に配置し、養液循環装置２により養液タンク２０内の養液を、最上段容器の最高高さ位置に供給した後、上下に隣接する各段の容器において上段側容器の最低高さ位置から下段側容器の最高高さ位置に自然流入させるとともに、最下段の容器の最低高さ位置から養液タンク内に自然流入させることで、養液を養液タンクと各栽培容器間で循環させるようにしている。【選択図】 図１
