A plurality of feedthrough capacitor chips are received in a single casing and retained therein in such a manner that the first outer terminals thereof are connected in common to a single earth plate formed of an electrically conductive member and installed in the casing. The lower end edge of the earth plate is exposed out of the bottom surface of the casing. On the other hand, the second outer electrodes of the feedthrough capacitor chips are respectively connected to terminals which extend to the outside of the casing.