A semiconductor chip including at least three variable capacity diodes for use at a frequency of 30 to 300 megaherzs is mounted on a grounding member so as to be sealed within a package. A plurality of external connection conductors each coupled to the diode and a plurality of external ground conductors coupled to the grounding member extend out of the package. Each ground conductor is disposed between the adjacent two of the external ground conductors. The arrangement permits a decrease of interference occurring due to a stray capacitance between the diodes.