The invention relates to the field of the protection of structures such as terrestrial buildings, vehicles or else ships, against attacks operated by means of hollow charges. It applies in particular to the protection of armoured vehicles.The subject of the invention is a module for embodying a lightweight and mobile reactive armour comprising at least one electrically conducting external wall and one electrically conducting internal wall and forming two electrodes between which is applied a very high voltage, the said walls defining an inter-electrode space, as well as an electrically conducting internal tridimensional mechanical structure, of low density, in electrical contact with the internal wall.The module according to the invention is intended to be placed between the object to be protected and the hollow charge, the internal tridimensional mechanical structure being positioned between the electrodes and the object to be protected.The module according to the invention makes it possible to increase the effectiveness the destruction of the jet by lengthening the destruction by fusion and vaporization during the traversal of the internal tridimensional mechanical structure.