A liquid-permeable panel is mounted on a portion of a system toilet for animals, and a 15-degree bending strength defined below the liquid-permeable panel is at least 0.2 N and no greater than 10 N. The 15-degree bending strength is the load that is applied at a velocity of 500 mm/min to the central section of the liquid-permeable panel from the direction perpendicular to a plan view using a round plunger having a diameter of 8 mm, while both sides in the Y-direction in a plan view of the liquid-permeable panel are being supported, that deforms the liquid-permeable panel into the shape of a concavity along the X-direction such that, in a cross section of the concavity, the angle (θ) formed by a horizontal line that contains the bottommost point of the concavity and an oblique line linking the aforementioned bottommost point and either of the aforementioned both sides is 15 degrees.
