A concentrator (10) of sun rays comprising: a reflective body (15) adapted to reflect incident sun rays towards a focal segment (SF) at which the reflected sun rays intersect, wherein the reflective body (15) comprises a plurality of reflective first sheets (40) alongside each other along a flanking direction parallel to the focal segment (SF) and each of which is inclined with respect to a planeperpendicular to a plane passing through the middle point (PM) of the focal segment (SF) and orthogonal to the focal segment itself, wherein each first sheet (40) comprises a reflective surface defined by a plurality of parabolas (401), which are alongside each other with respect to the flanking direction of the first sheets (40) and each have a vertex (Vn1) placed on a vertex segment (SV1), whichjoins all the vertices (Vn1) of the parabolas (401) of each first sheet (40) have a focal distance varying along the flanking direction and are configured such that each parabola has a focal point (F1, Fn1, F2) placed on the focal segment (SF).