A groove, and a recess which communicates with the groove, are formed in a substrate. Next, a through hole which communicates with the groove is formed. Thereafter, a wire is formed on an upper surface of the substrate, and an individual electrode is arranged on a lower surface of the substrate. Further, a droplet of an electroconductive liquid is made to land on the recess, and the liquid is filled in the through hole via the groove. Next, the liquid filled in the groove, the recess, and the through hole is heated to harden. Further, the recess and the groove of the substrate are removed by cutting up to an area near the through hole. Accordingly, it is possible to connect electrically the connecting bodies arranged on both surfaces of the substrate by filling an electroconductive material in the through holes easily.