PURPOSE: To make a material which excels in the resistance against bending and the quality of etching and at the same time perform the working processes in continuity.

CONSTITUTION: A flexible insulating film 101 is printed with resist by a printer 103 and then transferred into a vacuum chamber 105 through a continuous sealing device 104. Next, sputter-etching is applied to the film surface or ultra- violet rays are applied thereto by an ultra-violet ray emitting device 106 for etching and then the preliminary film of an electrically conductive metal is formed by a sputtering device. Next, a metal film is formed with the evaporation process continued by a vacuum evaporation device 108 until the film thickness reaches a predetermined thickness, and a through-hole is made therein by a through-hole working device 109, and besides after the processes of electroless plating and resist separation are respectively performed by using an electroless plating tank 110 and a resist separation tank 111, a cover film 112 is applied to the surface of the base board.