The present invention concerns a support device (1) for hydroponic cultivation comprising a panel formed by a substantially parallelepiped hollow body, apt to float on a culture liquid and comprising a plurality of seats (30) containing blocks of growth substrate, said seats (30) being each defined by a top opening (31), lying on the top surface (21) of the panel (1), and a lower opening (32) lying on the lower surface (22) of the panel (1), and by a continuous lateral wall (33). In particular, said top openings (31) have an essentially square shape, said lower openings (32) having an essentially circular shape, and the diameter (D2) of each of said lower openings (32) has a smaller dimension than the dimension of the side (D1) of the corresponding top opening (31).
