The present invention relates to a fuel injector. The fuel injector is provided with an injection nozzle, an injection valve, and an electromagnetic actuator. The injection valve has a movable needle to adjust the flow of fuel through the injection nozzle. The electromagnetic actuator is adapted to move the needle between a closing position and an opening position of the injection valve and is provided with a movable plunger which is mechanically connected to the needle and has at least one feeding through hole for the passage of fuel towards the injection nozzle. The plunger is provided with a hydraulic type braking device, which is coupled to the feeding hole and hydraulically dissipates kinetic energy to slow down the opening stroke of the needle when the needle moves towards the opening position of the injection valve.