An electric circuit device comprises an electric connecting member comprising a support member made of an electrically insulating material and a plurality of electrically conductive members buried in the support member and being isolated from one another. The ends of one side of the electrically conductive members are exposed at one surface of the support member, and the ends on the other side of the electrically conductive members are exposed at another surface of the support member. A first electric circuit component has connecting regions connected to the one set of ends of the electrically conductive members, and a second electric circuit component has connecting regions connected to the other set of ends of the electrically conductive members. Some of the electrically conductive members can be arranged in a zigzag pattern, and the pattern of the exposed ends of at least one electrically conductive member is wave-like or S-like.