A fastening staple adapted for fastening of a photovoltaic framework against a front face of a support wall, the fastening staple consisting of an electrically-conductive metallic part integrally made in one piece shaped so as to delimit: - a bearing head; - a counter-support foot; - a linking body linking the counter-support foot to the bearing head so that the bearing head and the counter-support foot are shifted from each other along a longitudinal direction of the fastening staple by a determined interval, the linking body being adapted to cross the thickness of the support wall through a slot formed in the support wall, by longitudinal insertion of the bearing head through the slot so as to position the bearing head and the counter-support foot respectively on either side of the support wall, and to slide along the slot by an overall sliding movement of the fastening staple in a transverse direction of the fastening staple; wherein the determined interval between the bearing head and the counter-support foot is adapted such that the bearing head and the counter-support foot constitute a jaw likely to transversely receive both a segment of the support wall and a segment of the photovoltaic framework in a configuration where the photovoltaic framework bears against the front face of the support wall, wherein the counter-support foot comprises at least one bearing lateral flange positioned longitudinally so as to bear longitudinally against a rear face of the support wall when the photovoltaic framework and the support wall are transversely engaged in the jaw, wherein the bearing head comprises at least one hooking element adapted to hook the photovoltaic framework in order to transversely immobilize the photovoltaic framework in the jaw, wherein the bearing head and/or the counter-support foot comprises at least one mechanical tensioning flange where an elastic deformation and/or a displacement thereof, resulting from the action of transverse engagement of the photovoltaic framework segment and of the support wall segment in the determined interval between the bearing head and the counter-support foot, enables the bearing head and the counter-support foot to exert a longitudinal tightening of the photovoltaic framework and of the support wall in the jaw, the fastening staple being characterized in that the linking body is constituted by two lateral walls delimited by the fastening staple, shifted from each other in a lateral direction of the fastening staple and connected to each other at one of their longitudinal ends at the bearing head by a folding area, their opposite longitudinal ends being independent of each other at the counter-support foot, said at least one bearing lateral flange being secured to one of the lateral walls so as to extend laterally in projection with respect to the lateral wall to which it is secured. - a bearing head; - a counter-support foot; - a linking body linking the counter-support foot to the bearing head so that the bearing head and the counter-support foot are shifted from each other along a longitudinal direction of the fastening staple by a determined interval, the linking body being adapted to cross the thickness of the support wall through a slot formed in the support wall, by longitudinal insertion of the bearing head through the slot so as to position the bearing head and the counter-support foot respectively on either side of the support wall, and to slide along the slot by an overall sliding movement of the fastening staple in a transverse direction of the fastening staple;