PROBLEM TO BE SOLVED: To provide an absorbent article in which a foot is unlikely to be caught by a side sheet (leakage preventing wall portion) when a wearer passes the leg through an opening around a leg. An absorbent article (1) having an absorbent main body (10) and a pair of leak-proof wall portions (40) provided with elastic members (41), the pair of leak-proof wall portions being provided. The (40) has an inner leak-proof wall part (42) and an outer leak-proof wall part (43), respectively, and a fixing part (50) is provided in a crotch part, and the fixing part (50) is made of the elastic material. When the member (41) is extended, the outer end (43a) of the fixing portion (50) in the width direction in the longitudinal direction is Lo, the inner end (43b) is Li, and the elastic member ( 41) at the time of contraction, when the dimension of the outer end (43a) in the width direction of the fixing portion (50) in the longitudinal direction is Lo′ and the dimension of the inner end (43b) is Li′, (Li-Li')/Li>；(Lo-Lo')/Lo. [Selection diagram] Fig. 4【課題】着用者が脚回り開口部に足を通す際に、サイドシート（防漏壁部）に足が引っ掛かり難い吸収性物品を提供する。【解決手段】吸収性本体（１０）と、弾性部材（４１）を備えた一対の防漏壁部（４０）と、を有する吸収性物品（１）であって、前記一対の防漏壁部（４０）は、内側防漏壁部（４２）と外側防漏壁部（４３）とをそれぞれ有し、股間部において固定部（５０）が設けられ、前記固定部（５０）は、前記弾性部材（４１）の伸長時において、長手方向における、前記固定部（５０）の前記幅方向の外側端（４３ａ）の寸法をＬｏとし、内側端（４３ｂ）の寸法をＬｉとし、前記弾性部材（４１）の収縮時において、前記長手方向における、前記固定部（５０）の前記幅方向の外側端（４３ａ）の寸法をＬｏ´とし、内側端（４３ｂ）の寸法をＬｉ´としたときに、（Ｌｉ－Ｌｉ´）／Ｌｉ＞（Ｌｏ－Ｌｏ´）／Ｌｏである。【選択図】図４
