Abstract: Component parts are mounted on a top surface of a ceramic substrate having therein a ground line including a ground layer electrically connected to a grounding portion exposed on a bottom surface of the ceramic substrate. Then, the top surface of the ceramic substrate is coated with a mold resin layer. Half-cut is performed on the ceramic substrate from the surface of the mold resin layer to expose a portion of the ground line from a side surface of the ceramic substrate. A conductive shield film is so formed to cover the surface of the mold resin layer and the exposed portion of the ground line by the half-cut. A slit for dividing the ceramic substrate into individual electronic components is formed before the dividing the ceramic substrate. The ceramic substrate is divided into the individual electronic components by the slit.