Underpants-shaped disposable diaper

An underpants-shaped disposable diaper (1) is provided with: an absorbent main body (10) comprising an absorbent core (11); and a waist portion (20) that can be stretched and contracted in a transverse direction, in which it is assumed that a stretched state of the waist portion (20) when stretched in the transverse direction to the same size as a single sheet-like member constituting the waist portion (20) is defined as a maximum stretched state, the waist portion (20) has a region (71) in a maximally stretched state in at least a portion outside the absorbent core (11) in the transverse direction when the waist portion (20) is stretched in the transverse direction up to a size of 70% of the size of the single sheet member. 一种内裤状一次性尿布(1)，包括：吸收性主体(10)，所述吸收性主体包括吸收芯(11)；以及腰部部分(20)，所述腰部部分能够在横向方向上拉伸和收缩，其中，假设当所述腰部部分(20)的当在横向方向上被拉伸直到尺寸与构成所述腰部部分(20)的单个片状部件的尺寸相同时的拉伸状态被限定为最大拉伸状态，则当所述腰部部分(20)沿横向方向拉伸直至所述单个片状部件的尺寸的70％的尺寸时，所述腰部部分(20)具有在横向方向上位于所述吸收芯(11)外侧的至少一部分中的处于最大拉伸状态的区域(71)。