A conductor portion is formed on the surface of a support member. After the conductor portion is formed, a copper foil on which resin is attached is moved downward from above the conductor portion to pressurize the conductor portion while covering it. the copper foil with the resin is pressed to the height of the conductor potion while using the conductor portion as a stopper. Thus, it is possible to make the height of the insulating layer equal to the height of the conductor portion.