Abstract: Disclosed is a device for attaching a solar panel including at least two retaining elements, suitable for retaining a panel by engaging with two opposing parts of the solar panel, at least one of the retaining elements being movable in a direction defined by a guide system and in such a way as to allow an adjustment of the spacing between the two retaining elements. The device includes: an assembly including a fixed support and the mobile retaining element, the mobile retaining element and the fixed support consisting respectively of two synthetic parts, in particular two plastic parts, the guide system being produced by mutually engaging structures between the mobile retaining element and the fixed support produced as a one-piece component with the parts forming the fixed support and the mobile retaining element.