A fuel injector for an internal combustion engine is provided. The fuel injector is equipped with a fuel pressure sensor, a sensor circuit such as an amplifier, and a valve actuator such as a piezoelectric actuator. The fuel injector also includes a conductive shield which is disposed between the sensor circuit and actuator drive terminals to supply electric power to the actuator and works to shield the sensor circuit from electric noises arising from the drive terminals, thereby minimizing the addition of the noises to an output of the fuel pressure sensor, as being processed in the sensor circuit, and ensuring the accuracy in determining the pressure of fuel based on the output of the fuel pressure sensor.