A diaper includes first and second sheets having elastic strings, and a crotch section with an absorbent body connected to the first and second sheets. The first sheet includes two first margins, each of which is contiguous to one of first outermost edges, and a first notch that is indented inwardly from one of the first outermost edges to extend inwardly through and beyond the adjacent first margin. The second sheet includes two second outermost edges, two second margins. The second margins are thermal bonded respectively to the first margins to form thermal seams. The first notch forms a first opening contiguous to one of the thermal seams to provide good ventilation and to ease tearing of the diaper at the thermal seam.
