In the past years the Italian Research Aerospace Center (CIRA) has developed several simulation facilities able to reproduce in real time the behavior of manned and unmanned aircrafts, air traffic scenario and to emulate Air Traffic Management (ATM)/Air Traffic Control (ATC). In order to allow a simulation in which all these facilities interact among them, also including pilots and ground control station operators in the loop, a real-time Integrated Simulation Facility (ISF) was realized. The first purpose of the ISF is to perform, in a real-time simulation environment, the validation and verification of new ground and onboard systems through the simulation of complex scenarios. The second purpose of ISF is to develop, verify and optimize new procedure for the air traffic management. The paper will describe the ISF architecture, the HW/SW component and the operating modalities.