PROBLEM TO BE SOLVED: To provide a disposable diaper whose fastening tape cannot easily come off while worn but can be easily taken off a side flap in removal.SOLUTION: A disposable diaper comprises a side flap 14, a fastening tape 30 disposed on both side sections of the side flap in the width direction, and a joining section 40 for joining a part of the fastening tape to a non-skin-side of the side flap 14 in the thickness direction. In a deployed state, the magnitude of force (F1S) to peel off the joining section when a region of the fastening tape that is further outside in the width direction than the joining section has been drawn in a direction oriented outward along the width direction is greater than the minimum value of force (F2S) to peel off the joining section when a region of the fastening tape that is further inside in the width direction than the joining section has been drawn in any direction between the direction oriented outward along the width direction and a direction oriented outward along the thickness direction.SELECTED DRAWING: Figure 7【課題】着用時にはファスニングテープが外れにくく、取り外す際には容易にファスニングテープをサイドフラップから離脱させることが可能な使い捨ておむつを提供する。【解決手段】サイドフラップ14と、幅方向においてサイドフラップの両側部に配置されたファスニングテープ30と、厚さ方向においてファスニングテープの一部をサイドフラップ14の非肌側に接合する接合部40と、を備え、展開状態において、ファスニングテープのうち接合部よりも幅方向の外側の領域を、幅方向に沿って外側に向かう方向に引っ張った際に、接合部が剥がれるときの力(F1S)の大きさが、ファスニングテープのうち接合部よりも幅方向の内側の領域を、幅方向に沿って外側に向かう方向から厚さ方向に沿って外側に向かう方向までの間の任意の方向に引っ張った際に、接合部が剥がれるときの力の大きさ(F2S)の最小値よりも大きい。【選択図】図7
