Abstract: A heat-insulating panel, particularly adapted for walls of buildings, including two parallel thin ribbed metal sheets covering an intermediate layer, consisting of a heat-insulating resin, in which the said covering metal sheets show in positions corresponding to each other and at a regular distance undercut reliefs projecting on one face whereat there are inserted coupling organs of the said metal sheets, consisting of material having a low thermal conductivity, and on each projecting relief there are fixed movably fastening means to the support structures and the end portions of the two metal sheets are folded over and shaped so as to build a concave edge and a convex edge, which may be coupled by embedding with each other and provided on their inner surfaces with gaskets having a series of longitudinal lamellar reliefs, placed in intercalated positions.