A disposable diaper for pets, comprising: a back-side waist area； a stomach-side waist area； a crotch area； a tail insertion opening； an absorbent core； an area not having the absorbent core arranged therein； an attachment section in the stomach-side waist area； an attachment area that accepts the attachment section； an expandable/contractible elastic member for legs, arranged, in an extended state, in a prescribed area in the diaper longitudinal direction, between the absorbent core and an end section in the diaper longitude-intersecting direction； an expandable/contractible elastic member for the waist, arranged, in an extended state, in the area not having the absorbent core arranged therein, in the diaper longitude-intersecting direction； and a contraction force intersecting area in which the contracting force of the expandable/contractible elastic member for legs and the expansion/contraction force of the expandable/contractible elastic member for the waist intersect.
