The present invention relates to a support device (1) for hydroponic cultures formed of a panel made of polymeric material comprising a plurality of separate and distinct hollow tubular elements (2) arranged side-by-side and spaced apart in parallel so as to create a plurality of seats (20) suitable to contain an inert substrate for hydroponic cultures, each defined between two adjacent tubular elements (2) and extending between an upper opening (21) and a lower opening (22). In particular, said tubular elements (2) each have a shaped cross-section, defined by a curved top portion (2A) and a pair of flat and inclined side walls (2B) extending symmetrically with respect to a vertical axis (X-X) and diverging towards the outside, such that said seats (20) have a substantially "funnel-shaped" section.