PURPOSE: To improve shield effects by comprising the first insulating layer which coats the whole surface including the walls of through holes, second insulating layer which coats the surface of this insulating layer while blocking through hole openings, a conductive resin film to be formed over the surface of the second insulating layer, and an overcoat which coats the conductive resin film.

CONSTITUTION: A conductor 2 constitutes a through hole zone 7: the first insulating resist 3 coats lands and the substrate surface including the conductor wall of the through hole zone 7, and the second insulating resist 4 coats the surface of the first insulating resist 3 while blocking through hole openings. Further, a conductive resin film 5 and an overcoat 6 coat the surface of the second insulative resist. This way of coating through holes 7 and lands with a conductive resin film 5 can suppress radiant electromagnetic waves coming from lands. Thereby, through holes are coated with a shield layer of conductive resin film 5 with the result that nothing radiates from through holes.