A separating device for a ball mill or an agitator ball mill as well as a ball mill or agitator ball mill with a separating device, wherein the ball mill or agitator ball mill includes a cylindrical grinding container with a first end opening and a second end opening, wherein the first and second end openings can be closed by a first and a second closure device, wherein a ground stock inlet is arranged in the region of the second end opening and a ground stock outlet is arranged in the region of the first end opening and wherein the separating device is assigned to the ground stock outlet. The separating device includes a plurality of first and second screen segments with screen apertures, which are arranged in an alternating manner on a frame.