Lighting device using electrically powered lighting sources, in particular solid-state lighting sources such as LED sources, comprising: - a printed circuit board having a main side on which there are arranged side by side a plurality of said lighting sources, oriented so as to project the emitted light radiation in a direction perpendicular to the main side of the printed circuit board, - a first support body configured to support said printed circuit board in a horizontal direction and a second support body rigidly connected to said first support body so as to implement a single casing of said device, - said second support body including: - a seat set up to receive an end of the printed circuit board, in such a way that said lighting sources are arranged within said second support body, - a plurality of channel-shaped portions arranged side by side and extending in a direction substantially parallel to said horizontal direction, each having a first end facing towards said first support body and a second, opposite end defined by a lens, set up to emit the light radiation generated by a corresponding lighting source, in such a way that at an outer surface of said casing a plurality of said lenses are arranged side by side in an aligned series, - wherein each channel-shaped portion is configured to receive, in the proximity of said first end, a corresponding lighting source mounted on the printed circuit board, and to convey the light emitted from the corresponding lighting source towards the corresponding lens, - said lighting device further comprising a reflector element rigidly connected by means of connecting members to said second support body and arranged transversely along the first ends of the channel-shaped portions, said reflector element having a plurality of reflective surfaces arranged side by side, each facing towards a corresponding channel-shaped portion and configured to direct and to improve the homogeneity of the light rays emitted from a lighting source onto the corresponding lens. - a printed circuit board having a main side on which there are arranged side by side a plurality of said lighting sources, oriented so as to project the emitted light radiation in a direction perpendicular to the main side of the printed circuit board, - a first support body configured to support said printed circuit board in a horizontal direction and a second support body rigidly connected to said first support body so as to implement a single casing of said device, - said second support body including: - a seat set up to receive an end of the printed circuit board, in such a way that said lighting sources are arranged within said second support body, - a plurality of channel-shaped portions arranged side by side and extending in a direction substantially parallel to said horizontal direction, each having a first end facing towards said first support body and a second, opposite end defined by a lens, set up to emit the light radiation generated by a corresponding lighting source, in such a way that at an outer surface of said casing a plurality of said lenses are arranged side by side in an aligned series, - wherein each channel-shaped portion is configured to receive, in the proximity of said first end, a corresponding lighting source mounted on the printed circuit board, and to convey the light emitted from the corresponding lighting source towards the corresponding lens, - said lighting device further comprising a reflector element rigidly connected by means of connecting members to said second support body and arranged transversely along the first ends of the channel-shaped portions, said reflector element having a plurality of reflective surfaces arranged side by side, each facing towards a corresponding channel-shaped portion and configured to direct and to improve the homogeneity of the light rays emitted from a lighting source onto the corresponding lens.