Abstract: Structure of radioactive lightning conductor comprising, associated to the metal lightning rod, an insulator body acting as support for a source of radioactive emissions, said source being contained inside a container, which forms a chamber sealed against the direct outlet of radioactive emission, but which has openings of connection with the outward air, the chamber of said container being further connected to a gas source, apt to produce a gas flow from the inside to the outside of said container, through said openings.