A pet diaper is equipped with a front surface layer, a back surface layer, and an absorbent layer disposed between the front surface layer and the back surface layer. The pet diaper has a back portion, an abdominal portion, and a crotch portion disposed between the back portion and the abdominal portion. The pet diaper is further equipped with: a first cut portion that is provided on the back portion and that is formed as a convex curve rounding towards the end portion of the back portion； a second cut portion that is provided closer to the crotch portion than the first cut portion and that is formed as a convex curve rounding towards the end portion of the back portion； and a first perforated portion that is formed so as to extend from the second cut portion towards the first cut portion.
