Booster valve (4) for pneumatic circuits, comprising: a hollow body (5), a pilot flow inlet/outlet gap (15) communicating directly with a control volume (16), an inlet/outlet gap (45) communicating with an actuator and communicating directly with an accumulation volume (29), a supplying gap (53) communicating directly with a supplying volume (38), a discharge gap (44), an amplified discharge shutter (25) which determines the sealing towards the discharge gap (44), a central device (43) comprising an amplified charge shutter (32) which determines the sealing towards the supplying gap (53), an activation piston (22) which, subjected to the pressure acting in the accumulation volume (29) and in the control volume (16), determines the movement of the amplified discharge shutter (25) or the amplified charge shutter, and having two separated and independent charge (47) and discharge (46); gain control devices which allow an independent adjustment between the charge and the discharge step and vice versa, and the central device (43) comprising a plurality of stakes (33), which, in combination with the passage sections determined by the opening of the amplified discharge shutter (25) and the amplified charge shutter (32) determine the flow amplification in discharge and charge steps.