PROBLEM TO BE SOLVED: To provide a disposable diaper for a pet fitted satisfactorily for the waist of the pet.SOLUTION: A disposable diaper for a pet comprises: a back side waist； a belly side trunk periphery； a crotch area； two end portions in the diaper longitudinal direction； two end portions in a diaper longitudinal direction cross direction； a tail insertion opening； an absorbent core； an absorbent core non-arranged region； a fixing portion disposed in the belly side trunk periphery； a fixing area 900 for receiving the fixing portion； a leg periphery stretchable elastic member arranged in a predetermined area in a stretched state in the diaper longitudinal direction between the absorbent core and the end portion on the diaper longitudinal cross direction； a leg lampshade formed by the shrinkage of the leg periphery stretchable elastic member； a leg periphery stretchable elastic member arranged in a stretched state in said absorbent core non-arranged area in the diaper longitudinal cross direction； and a shrinking force intersecting area 180, in which the shrinking force of the leg periphery stretchable elastic member and the stretching force of the trunk periphery stretchable elastic member intersect.【課題】ペットの胴周りに対し良好にフィットするペット用使い捨ておむつを提供する。【解決手段】背側胴周り域と、腹側胴周り域と、股下域と、おむつ長手方向上における両端部と、おむつ長手交差方向上における両端部と、尻尾挿通開口と、吸収性コアと、吸収性コア非配置領域と、腹側胴周り域に設けられた止着部と、止着部を受ける止着領域９００と、吸収性コアとおむつ長手交差方向上の端部との間におけるおむつ長手方向の所定領域に伸長状態にて配置される脚周り用伸縮性弾性部材と、脚周り用伸縮性弾性部材の収縮により形成される脚周りギャザーと、おむつ長手交差方向における前記吸収性コア非配置領域に伸長状態にて配置される胴周り用伸縮性弾性部材と、脚周り伸縮性弾性部材の収縮力と胴周り用伸縮性弾性部材の伸縮力とが交差する収縮力交差領域１８０とからなるペット用使い捨ておむつ。【選択図】図１３
