PROBLEM TO BE SOLVED: To provide a hydroponic apparatus in which sliding lid bodies mounted on the top part of a long-sized water tank smoothly slide in a longitudinal direction of the water tank.SOLUTION: A hydroponic apparatus 100 comprises along-sized water tank 1, and sliding lid bodies 2 mounted on the top part of the water tank 1, in which the water tank 1 is constituted of at least two or more water tank bodies 10 whose cross section is in an approximate U-shape and a joint 11 which connects the water tank body 10 and the water tank body 10 in a longitudinal direction and whose cross section is in an approximate U-shape. The sliding lid body 2 is a long-sized plate-like body in which a plurality of insertion holes 3a holding plants 3 are perforated at a constant gap so as to position on an approximate center line L of the water tank 1 when the body is mounted on the top part of long-sized water tank 1, the joint 11 is formed such that its side plate 11b becomes gradually higher toward the center, and constituted such that the side plate is at the same or higher position as/than a higher one of sidewall upper ends 10b,10b of adjacent water tank bodies 10,10.SELECTED DRAWING: Figure 1
