A disposable diaper 10 has sheet-like leg hole stretch units 100 that extend in a product lengthwise direction L in an area where leg hole concave units 35 are formed and are at least partially stretchable along a product lengthwise direction L. End edges in a product widthwise direction W of the leg hole stretch units 100 undulate in the product lengthwise direction L. Distances between the end edges in the product widthwise direction W of the leg hole stretch units 100 and a center line CL change from a front waistline unit 20 towards a rear waistline unit 30. There are provided a plurality of inflection points where an amount of change along the distance starts decreasing instead of increasing and a plurality of inflection points where an amount of change along the distance starts increasing instead of decreasing, respectively.