An apparatus for pressurizing an aircraft cabin structure and measuring the amount of leakage of the aircraft cabin structure comprises an air supply line which at a first end is connectable to a pressurized air source and which at a second end is connectable to the aircraft cabin structure so as to supply pressurized air from the pressurized air source into the aircraft cabin structure, an air supply valve disposed in the air supply fine, a pressure sensor for sensing the pressure inside the aircraft cabin structure and for providing signals indicative of the pressure inside the aircraft cabin structure, an air discharge line which at a first end is connectable to the aircraft cabin structure and which at a second end is connectable to an air discharge opening so as to discharge air from the inside of the cabin structure to the air discharge opening and an air discharge valve disposed in the air discharge line. An electronic control unit is adapted to control the air supply valve and the discharge valve in dependence on signals provided by the pressure sensor.