A litter box for a domestic animal includes a box-like body equipped with an upper support wall that has a through opening, a container of a granular litter material susceptible to absorb the animal excrements, and a first tubular duct arranged below the upper wall, which is substantially extended between the upper wall and the bottom of the body, for conveying the animal excrements towards a discharge zone in the lower part of the body. The receptacle surrounds a second tubular duct inside the first tubular duct, whose upper end faces the opening and whose lower end faces the bottom of the body, and which defines an internal edge of the receptacle for the purpose of retaining a quantity of the granular material therein.
