Provided is an absorbent article capable of better securing a space for accommodating excreta on the buttock side during wearing. An absorbent article (10) has a front-rear direction, a width direction orthogonal to the front-rear direction, a front waist region (S1), a rear waist region (S2), a crotch region (S3) between the front and rear waist regions, and an absorbent core (51) provided at least in the crotch region. A fold line (FL) for folding the absorbent article in half extends along the width direction in the crotch region. The absorbent core has a constriction area (CA) which is constricted inwardly in the width direction at least in the crotch region, and a pair of grooves (54) formed on both sides with respect to the center of the absorbent article in the width direction. The constriction area extends in the front-rear direction with respect to the fold line. The absorbent core has a rear widening portion (54r) in which the distance between the pair of grooves increases with the transition in the rearward direction. A front end edge (54s) of the rear widening portion is located in the area overlapping with the constriction area ahead of the fold line.提供一種在穿著中可以更確保由臀部側收容便的空間的吸收性物品。吸收性物品(10)，是具有：前後方向、及朝前後方向垂直交叉的寬度方向、及前胴周圍域(S1)、及後胴周圍域(S2)、及前胴周圍域及後胴周圍域之間的股下域(S3)、及至少設於股下域的吸收芯(51)。將吸收性物品對折用的折線(FL)，是在股下域沿著寬度方向延伸。吸收芯，是具有：至少在股下域中朝寬度方向的內側收縮的狹窄領域(CA)、及對於寬度方向中的吸收性物品的中心形成於兩側的一對的溝(54)。狹窄領域，是有關折線朝前後方向延伸。吸收芯，是具有隨著一對的溝彼此之間的間隔朝向後方而擴大的後方擴寬部(54r)。後方擴寬部的前端緣(54s)，是位於比折線更前側且與狹窄領域重疊的領域。
