A fastening system for a wearing article comprising a pair of hook carrying side edge portions with a hook component and a pair of loop carrying side edge portions with a loop component adapted to be detachably engaged with each other. Each of the hook carrying side edge portions comprises a first sheet section extending outward from each of the transversely opposite side edges of the wearing article, a second sheet section being contiguous to an outer side edge of the first sheet section so as to extend toward the transverse side edge, a joining area extending in parallel to and spaced from the outer side edge so as to join the first and second sheet section to each other, and a non-joining area surrounded by the joining area, the first and second sheet sections and the outer side edge, and the hook component has first and second edges extending in parallel to the outer side edge and is secured to the hook carrying side edge portion in such a manner that the first side edge lies in the joining area while the second side edge lies in the non-joining area.