A disposable diaper for pets, in which part of a crotch area stands up as a result of the contraction of an expanding/contracting elastic member, and a standing-up section is formed, said disposable diaper for pets having: a rear-side waist area a stomach-side waist area the crotch area both end sections in the diaper longitudinal direction both end sections in the diaper longitude-intersecting direction a tail insertion opening an absorbent core an attachment section provided in the stomach-side waist area an attachment area that receives the attachment section and the expanding/contracting elastic member arranged the diaper longitudinal direction.
