The absorbent body (40) of this disposable diaper (10) is provided with: a first region (41) from the end (40R) at the back waist-encircling region of the absorbent body to the groin region (25) side； and a second region (42) that has a lower bending rigidity than the first region (41) and is disposed adjacent to the first region (41) at the groin region (25) side of the first region (41). The ends (75R) at the back waist-encircling region (30) side of leg expansion/contraction section (75) and the ends (84R) at the back waist-encircling region (30) side of the contracted section (84) of leg side expansion/contraction sections are disposed at the groin region (25) side of the ends (41R) of the first region (41) at the back waist-encircling region (30) side, and are disposed at the back waist-encircling region (30) side of the ends (41F) of the first region (41) at the groin region (25) side.
