PURPOSE: To make the thickness of a solder layer uniform by providing a copper-plated layer, which is formed only at a pad for component mounting and a through-hole, a solder-plated layer, which are formed on its top, an etching resist layer, which is formed on the top of a circuit pattern, and a solder resist layer, which is formed on its top.

CONSTITUTION: A through-hole 20 is bored in an insulating substrate 2 fitted with a copper foil 1, and a desired insulating resin pattern 3 is formed, and treatment by catalyst 4 is applied, and film-shaped photosensitive resin 5 is laminated on the obverse and reverse of the insulating substrate 2, and using a film in a desired pattern a plate resist pattern 5a is formed. Electroless copper plating is formed only at the through-hole 2 and a pad for component mounting, and further electroless copper plating is formed, and a layer of copper plating 6 is formed, and further solder plating 7 is deposited on the top of the electroless copper plating, and the plated resist pattern 5a is exfoliated and removed. The exposed place of the copper foil 1 is removed by ethcing so as to get a circuit pattern 1a, and further a solder resist 8 is formed.