A fastening element with less jamming during operation includes a plurality of a unit fastening element arranged adjacently, each unit fastening element including a filament section, an inserting head section equipped with a suitable engagement section located at one end of the filament section, and a socket section equipped with a hole for irreversibly passing the inserting head section located at the other end of the filament section, where a plurality of the socket sections or their vicinities arranged adjacent to each other are temporarily fixed to the connection bar section individually installed, respectively, and a plurality of optional filament sections adjacent to each other are separably fixed temporarily.