PURPOSE: To easily form vias at a high density wiring pattern by forming a lower layer conductor pattern on a ceramic wiring board, on top of that, performing wire-bonding where vias are formed, and forming an insulation layer and an upper layer conductor film after the wire is cut off.

CONSTITUTION: In the via formation process for a film type multilayer wiring board, a base material polyimide resin layer 11 is formed on a ceramic wiring board 10, and on top of that, a copper pattern 12 is formed as a lower layer conductor film. Then after a nickel layer 13 and a gold layer 14 are sequentially plated, a gold wire 16 is wore-bonded where interlayer connection is performed. Further, a gold wire 15 is cut to a specified length for forming vias (gold wire part) 16, and a polyimide resin 17 is applied up to the height of the via 16 and then cured. And then an upper layer conductor film 18 is formed. And the upper layer conductor film 18 and the copper pattern 13 are connected together with the preformed via 16 in between. With this method. the plating process for forming vias can be omitted, for reduced number of processes.