A pull-on diaper 50B of the invention includes an outer cover assembly 3 defining the exterior surface of the diaper. A front body portion F and a rear body portion R of the outer cover assembly 3 are connected to each other along their laterally opposite side edges to form a pair of side seams 4, a waist opening 8, and a pair of leg openings 9. Each side seam 4 has a sealed edge potion 41 where the front body portion side edge 3F and the rear body portion side edge 3R of the outer cover assembly 3 are bonded to each other at a continuous linear fusion bond extending in the longitudinal direction of the side seam and, in part, a non-sealed portion 42 where the front body portion side edge 3F and the rear body portion side edge 3R of the outer cover assembly face to each other in a non-bonded relationship.
