PURPOSE: To easily realize a punched pattern by forming a hardly etchable metallic layer having a slow etching speed on at least one surface of an easily etchable metallic layer having a faster etching speed with a conductive etching stopping resin layer having an adhesive property in between.

CONSTITUTION: An easily etchable metallic layer 2 having an etching speed which is slower than that of an easily etchable metallic layer 1 is formed on at least one surface of the metallic layer 1 with a conductive etching stopping resin layer 6 having an adhesive property in between. Accordingly, the easily and hardly etchable metallic layers 1 and 2 can be piled up upon another with the resin layer 6 in between to form a sheet metal and a punched pattern of an insulating section can be obtained easily by an etching process. Therefore, end faces facing each other in the punched pattern can be stabilized in shape and the distance between the facing end sections can be reduced.