A fastening device (4) molded of a synthetic resin material and adapted to be engaged with a large number of loops (11a) on one surface of a fastener part (11) of a mating member (1) includes a base member (42) having on its one surface a large number of hooks (43) integrally molded with the base member and arranged in a plurality of rows (R). The hooks in each hook row generally have the same hook direction aligned with an axis of the hook row, and the hooks in one hook row and the hooks in an adjacent hook row do not always have the same hook direction. At least one hook (43a) in each hook row (R) which is adjacent to a peripheral edge of the base member have a hook direction facing outwardly away from the peripheral edge. With this arrangement, the hooks located adjacent to the peripheral edge are capable of withstanding undue force tending to fatigue and eventually break the hooks. <IMAGE>
