A disposable diaper 1 including a panel structure 2 composed of a base sheet 4 and a core 5 attached thereto and a sheet member 9 extending above the panel structure 2. The panel structure 2 has a pair of first side slaps 6 extending in a longitudinal direction and a pair of end flaps 7 extending in a transverse direction. The sheet member 9 includes a pair of side walls 10 biased to rise above the panel structure 2 and a top wall 11 biased to be spaced upward from the panel structure 2. The side walls 10 have side edge portions bonded to the vicinity of transversely opposite side edges of the core 5 and first end portions bonded to the end flaps 7. The top wall 11 has an opening defined between the side walls 10, second end portions bonded to the end flaps 7 and second side flaps 12 extending outside the top edges of the respective side walls 10 in parallel to the first side flaps 6. Transversely opposite side edge portion of these flaps 6, 12 overlapping each other in the front and rear waist regions 20, 22 are bonded to each other.
