To provide a small, thin and light-weighted composite sensor which can also detect light together with sound, vibration, pressure or acceleration by a single sensor.
An electret capacitor type composite sensor is constituted by a casing 11, an electrode 12, a hole portion (which is a sound hole and also a light introduction hole) 22, a spacer 31, a vibration plate 41 having light transmissibility, a vibration plate ring 42, a printed board 6 and a semiconductor element 61. Further, a photoelectric conversion portion having a function of photoelectric effect is provided at a portion of the surface of the semiconductor element 61, light is conducted to the photoelectric conversion portion via the hole portion 22 and the vibration plate 41 having light transmissibility, and an electric signal generated by the photoelectromotive force is taken out independently from an electric signal generated by the change of the electrostatic capacitance of the electret capacitor.