A fuel injector has an injection valve having a movable pin terminating with a shutter head; a tubular supporting body having a feed channel; and a sealing body, in which a valve seat of the injection valve is defined; the shutter head is truncated-cone-shaped, is located outside the sealing body, and, in a closed position, is pushed against the sealing body in the opposite direction to the fuel feed direction; the pin has a stop member, which is integral with the pin and comes to rest on a top surface of the sealing body, when the pin is in the open position opening the injection valve, so as to determine travel of the pin.