PROBLEM TO BE SOLVED: To provide an underpants type absorbent article which is excellent in cushion property in a thickness direction, which can reduce heating during wearing, and which can softly cover a hip of a wearer on a back side extension part.SOLUTION: In an underpants type absorbent article 1, a length of a back side sheet member 2B is longer than a length of a side seal part S, and a back side body part 20b and a back side extension part 21b are provided. In the back side body part 20b, an outside sheet 22 and an inside sheet 23 are jointed each other on body part joint parts 26, and in teh back side extension part 21b, the outside sheet 22 and the inside sheet 23 are jointed each other on extension part joint parts 27. In a stretched state of a diaper 1, joint part rows 26L of the body part joint parts 26 are intermittently arranged in a Y direction, and in one joint part row 26L1, at least one of plural extension part joint parts 27 disposed below the joint part row 26L1, is configured so that, a center of the one extension part joint part is deviated to the Y direction from the center of the body part joint parts 26 forming the joint part row 26L1.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2017,JPO&INPIT
