PROBLEM TO BE SOLVED: To provide an underpants type absorbent article in which an absorbent body is hardly affected by contraction of a belt part.SOLUTION: In an underpants type absorbent article (1) including an absorbent body (10) and a pair of belt parts (20, 30), the belt parts (20, 30) have an elastic member (23, 33) which is joined between a skin side sheet (21, 31) and a non-skin side sheet (22, 32) by an adhesive and can expand and contract in a lateral direction and have a pair of joining parts (60) in which a non-skin side surface at an end part in a longitudinal direction of the absorbent body (10) and a skin side surface of the skin side sheet (21, 31) are joined. A basis weight of a fiber of the skin side sheet (21, 31) is greater than that of a fiber of the non-skin side sheet (22, 32), and the amount of the adhesive that joins the elastic member (23, 33) and the skin side sheet (21, 31) per a unit length is smaller than the amount of the adhesive that joins the elastic member (23, 33) and the non-skin side sheet (22, 32) per a unit length.SELECTED DRAWING: Figure 5【課題】吸収性本体がベルト部の収縮の影響を受け難いパンツ型吸収性物品を提供すること。【解決手段】吸収性本体（１０）と一対のベルト部（２０，３０）を有するパンツ型吸収性物品（１）であり、ベルト部（２０，３０）は、肌側シート（２１，３１）と非肌側シート（２２，３２）の間に接着剤で接合されている横方向に伸縮可能な弾性部材（２３，３３）を有し、吸収性本体（１０）の長手方向の端部の非肌側面と、肌側シート（２１，３１）の肌側面とが接合されている一対の接合領域（６０）を有し、肌側シート（２１，３１）の繊維の坪量が非肌側シート（２２，３２）の繊維の坪量よりも大きく、単位長さ当たりの弾性部材（２３，３３）と肌側シート（２１，３１）を接合している接着剤の量が、単位長さ当たりの弾性部材（２３，３３）と非肌側シート（２２，３２）を接合している接着剤の量よりも少ない。【選択図】図５
