PURPOSE: To reduce the radiation noise of a high frequency even in case a high-frequency circuit is built in an integrated circuit and to prevent the generation of the erroneous operation of this integrated circuit itself and the generation of the erroneous operation of other integrated circuits, which is interconnected to the integrated circuit, by a method wherein a high-frequency noise filter is provided outside an integrated circuit chip in the interior of a package.

CONSTITUTION: A high-frequency noise filter 7 is provided outside of an integrated circuit chip in the interior of a package. A filter constituted in such a way that inner leads 3... penetrate a high-magnetic material for high-frequency use, such as a tabular or cylindrical ferrite core, is used as the filter 7. In this case, it is possible to install the high-magnetic materials divided into two of an upper part and a lower part, for example, in such a way as to hold the leads 3... between the divided high-frequency materials from upward and downward. Thereby, a high-frequency choke coil results in being inserted in the leads 3... and it becomes possible that a high-frequency noise to go in and out through a Vcc power terminal, an earth potential (Vcc) terminal, an input terminal, an output terminal and the leads 3... for input/output terminal use is made to attenuate.