Abstract: A photovoltaic panel fastener and a device for mounting a panel module. The panel fastener, capable of cooperating with threaded fasteners to attach an assembly frame of the panel to a support structure, includes: a main body; a threaded connector extending perpendicularly to the body and having a passage for receiving the threaded fastener, and the inner wall of the passage of which is provided with an inner thread; a pair of clamping elements extending from the end surface of the body and being disposed along the first direction and symmetrical with respect to the central axis of the threaded connector; and a pair of support elements being disposed along the second direction and symmetrical with respect to the central axis. Each support element is connected to a clamping element and extends beyond the free end of the clamping element.