A plurality of surface-mounting components are mounted on a mother printed-circuit board provided with component-connecting electrodes, engagement holes, and case-fixing electrodes provided inside the engagement holes. Soldering paste is applied in the vicinity of the engagement holes or in an area covering a portion of each of the engagement holes and the vicinity of the engagement holes on the mother printed-circuit board from the side of the component-mounted surface such that soldering paste is not entirely filled in the engagement hole. A plurality of shielding cases are engaged in the mother printed-circuit board by inserting engagement protrusion portions of the shielding cases into the engagement holes. Then the engagement protrusion portions of the shielding cases are soldered to case-fixing electrodes inside the engagement holes by melting solder in the soldering paste. The mother printed-circuit board is then cut and divided into individual electronic components.