PURPOSE: To obtain a through hole in which a film defect is not caused by a method wherein a photoresist film is formed in a part other than the inside of the through hole and the region of a pattern formation part on a thin-film conductor layer, an Au-plated layer is formed on the pattern formation part and a thin-film resistance layer and the thin-film conductor layer are patterned by making use of the Au-plated layer as a mask.

CONSTITUTION: A thin-film resistance layer 2 is formed on the surface and the rear of an insulating board in which a through hole 6 has been made; a thin-film conductor layer 3 composed of Ti and Cu is formed sequentially on the thin-film resistance layer 2. A photoresist film 4 for plating is formed in a region excluding the inside of the through hole 6 and a pattern formation part on the thin-film conductor layer 3; after that, an Au-plated layer 5 is formed on the pattern formation part. Then, the photoresist film is removed; after that, the thin-film conductor layer 3 and the thin-film resistance layer 2 are patterned by making use of the Au-plated layer as a mask. Thereby, it is possible to select an etchant which does not etch the Au-plated layer in the through hole 6, and it is possible to obtain the through hole in which a film defect is not caused.