PROBLEM TO BE SOLVED: To provide a pet toilet, usable from pet infancy to the period of its growth and thereafter.SOLUTION: The pet toilet: an outer container 10 and an inner container 20, wherein an outer side low sidewall section 15 with low sidewall height is provided by cutting off part of the sidewall 12a of the outer container 10, while an inner side low sidewall section 25 with low sidewall height is provided by cutting off part of the sidewall 22a of the inner container 20. In this toilet, by laying the inner container 20 in the outer container 10 through making the respective positions of the outer side low sidewall section 15 and the inner side low sidewall section 25 coincide with each other, a pet entry section 2 is ensured to form； while the pet entry section 2 is closed by a wall section height-adjusting means.
