A solid-liquid separating apparatus is provided with: a separating roll which has a substantially cylindrical shape with a plurality of through holes, which penetrate between an inner surface and an outer surface in radial direction thereof, and is rotatable in circumferential direction thereof; and a pair of separating filter cloths which is endless belts capable of traveling in a rotation direction of the separating roll and are wound around the outer circumference of the separating roll so as to overlap each other, wherein a material supplied between the pair of filter cloths is squeezed by being rolled together with the pair of filter cloths therebetween on the outer circumference of the separating roll, and the material is dehydrated by ventilating via each through hole.