The present invention aims to restrict undesirable irritation to the wearer's skin, on one hand, and to protect the wearer's skin from contamination with body waste, on the other hand. The diaper is provided on a liquid-absorbent panel (23) with a barrier sheet (3) and leak-barrier cuffs (4) both extending in a longitudinal direction (Y). The leak-barrier cuffs (4) raise themselves apart from the liquid-absorbent panel (23) and the barrier sheet (3) is pulled upward as well as outward in a transverse direction (X) under contraction of cuff-biasing elastic members (50). Front joint zones extend from a front end (27) to points lying aside from a front center line (r-r) toward the middle zone (32) and front segments (39a, 40a) of first and second barrier sheet-biasing elastic members (39, 40) have front maximally spaced points (41, 42) to define the maximum distance (W2) between the points (41, 42). Rear joint zones extend from a rear end (28) to a rear center line (s-s) and rear segments (39b, 40b) of the respective elastic members (39, 40) have rear maximally spaced points (43, 44) between which the rear segments (39b, 40b) are maximally spaced from each other.