An open-type disposable diaper (1) includes a crotch stretch unit (200a) formed in an absorber arrangement region where an absorber (40) is arranged in a crotch region (25) and being stretchable in a product longitudinal direction (L) ； a pair of leg stretch units (75) formed along a leg hole openings (35) and being stretchable in at least the product longitudinal direction (L)； and a waist stretch unit (100) formed in a back waistline region (30) and being stretchable in a product widthwise direction (W) ； the absorber core arrangement region (300), enclosed by the crotch stretch unit (200a), the leg stretch units (75), and the waist stretch unit (100) and configuring the absorber (4), is formed so as not to be stretched； and the length (L2) of the absorber core arrangement region (300) in the product longitudinal direction (L) is configured to be longer than half the length (L1) of the crotch stretch unit (200a) in the product longitudinal direction (L).
