Abstract: The invention relates to a gas pressure regulator having a valve, a delivery duct of low pressure gas (Pb), a regulation shutter for the gas delivery flow, a control head of the valve defining an upper chamber [(9)] and a lower chamber. A pilot valve controls the movement of the shutter. The pilot valve has a first chamber with an inlet way, a first outlet way communicating with said delivery duct and a second chamber in which there is the body of an interception shutter adapted to open or close the inlet way [(14)]. The first chamber has at least a second outlet way communicating with the lower chamber and the upper chamber and the inlet way are connected to each other through an auxiliary duct containing gas at an intermediate pressure (Pm) between high pressure (Pa) and low pressure (Pb).