Abstract: A filling pistol for the filling under pressure of an object essentially with nitrogen. The filling pistol has a housing with an inlet opening connectable to an air source, such as an air compressor, to supply air to the pistol. A separation device is incorporated downstream of and connected to the inlet opening to obtain essentially nitrogen-rich gas. An outlet opening is connected to the separation device and is connectable to the object to supply nitrogen-rich air from the filling pistol to the object. The separation device is provided between the air inlet and the nitrogen outlet of an exchangeable separation cartridge. An operating element sets the filling pistol to an operating condition to fill the object with nitrogen-rich air.