Abstract: The invention concerns a shelter device in the form of a box-like structure for the protection of electronic apparatuses against atmospheric agents.The shelter comprises walls of insulating material forming a thermal resistance, as well as an amount of material(s) having a high specific heat operating inside the structure and forming a thermal capacity, the thermal resistance and capacity being able to maintain a shelter inner temperature that is constant and is correlated to the outer mean temperature over a time period of at least 24 hours.