A separating device separates liquid absorbent fibers from a material including the liquid absorbent fibers of an absorbent article and impurities. The separating device includes: a case； an insertion port for inserting the material into the case on an airflow； a rotation member in the case for agitating and opening the material； and a discharge port for discharging the liquid absorbent fibers from inside the case on an airflow. The rotation member rotates around a center axis from the insertion port to the discharge port, and the rotation member has protruding sections protruding outward in a direction that intersects with the center axis in a plurality of positions in the axial direction. A regulating member is provided in a predetermined position between the insertion port and the discharge port in the case, and the regulating member regulates movement of the material from the insertion port to the discharge port.
