An assembly component of a compression joint member that connects a power-transmission line to a connection target, includes a core portion compression member including a housing hole that houses an end portion of the core portion, and a compression portion that is compressed for compressing and connecting the end portion of the core portion housed in the housing hole; and a conductive portion compression member that houses an end portion of the conductive portion and the core portion compression member, and is to be compressed with the end portion of the conductive portion and the core portion compression member, wherein the compression portion includes an inclined portion provided at an opening side of the housing hole and whose outer diameter becomes smaller toward the opening side of the housing hole.