A support device of technological systems for walls, provided with at least a layer of plates (2), includes: first section bar means (3), having an elongated shape, each one including a first element (4) with "C" cross section whose edges have respective folded borders, first (5) and second (6), defining a longitudinal opening (10) of section bar means (3); fixing means (7) each one provided with at least first lip means (8) and first blocking means (9). In an assemblage condition (M) of device (1), the first section bar means (3) are fit for containing and supporting connection elements (50) of the system by means of respective first elements (4) and the second folded border (6) supports the plates (2) of the wall layer. The first lip means (8) of fixing means (7) are interposed between the first folded border (5) and said plates (2) and the first blocking means (9) are fit for fixing interconnection elements (51) of technological system to respective openings of the wall layer and to longitudinal openings (10) of the first section bar means (3).