[PROBLEMS] A disposable diaper in which deformation of an absorption core does not cause separation of the joint between an inner body and a belly-side or rear-side outer sheet nor does it cause deterioration in appearance and wearing comfort. [MEANS FOR SOLVING PROBLEMS] In the disposable diaper, a front end section of the inner body (20) is connected to the inner surface at the lateral center of the belly-side outer sheet (12F), a rear end section of the inner body (20) is connected to the inner surface of the lateral center of the rear-side outer sheet (12B), and the belly-side outer sheet (12F) and the rear-side outer sheet (12B) do not continue to each other on the crotch side. The disposable diaper is constructed to satisfy the relationships of 90 mm = W1 < W2 = 190 mm, 0 mm = L1 - L2 = 70 mm, and 0 mm = L3 - L4 = 50 mm, where L1 is the length of an absorption-core front end section (56F), L2 the length of the portion of overlap between the absorption core (56) and the rear-side outer sheet (12B), L3 the length of an absorption-core rear end section (56B), L4 the length of the portion of overlap between the absorption core (56) and the rear-side outer sheet (12B), W1 the width of a narrow section (56N), and W2 the width of the absorption-core front end section and the absorption-core rear end section.
