To improve insulation resistance after fusing and reliability, by forming connection wirings with electrodes positioning current protecting elements, on the parts of holes for gap formation where unnecessary parts of a metal foil thinned to be a specified thickness are eliminated, and performing cutting at the parts of holes between adjacent current protecting elements.

A very thin copper foil or a very thin copper foil with aluminum carrier is used for a metal foil of 3-9 μm in thickness. Two insulating plates 11, 12 formed by etching and eliminating copper foils of both surfaces of a laminated plate stuck on both surfaces of the metal foil are made first and second insulating layers. Two insulating plates 101, 102 with resin films are formed, and holes 4 for gap formation are made. A board on which current protecting elements 8 and connection wirings 71 are formed, the insulating plate 102 with resin film, a resin film 3 where holes are made in parts of the holes 4 for gap formation and a copper foil 72 of 18 μm in thickness are stuck on the single surface. Thus laminated plates 111, 112 are formed. The laminated plates 111, 112 where two copper foils 72 are arranged on the upper sides and the lower sides are so laminated in order while the holes 4 are aligned with parts of the elements 8.