an apparatus for reducing an electro - magnetic interference noise of an electronic device during supplying of power from a charging device . includes common mode choking coils to permit the electronic device to conform to various national standards regarding emissions of radiation . the cmcc can be arranged in the charging device and a power supply line of the electronic device or in an earphone connected with the electronic device or interposed there between . the higher frequency of radiation noise is reduced while dc levels are not affected by the choking coils . the radiation noise being emitted from the electronic device at the time of interworking with the charging device is greatly reduced .