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, while the material is made to ride on an airflow a rotation member housed in the case, the rotation member agitating and opening the material and a discharge port for discharging the liquid absorbent fibers, of the material that has been opened with the rotation member, from inside the case, while the liquid absorbent fibers are made to ride on an airflow. The rotation member has a revolving axis and a shaft member, the revolving axis being set with an axial direction along a predetermined direction from the insertion port to the discharge port, the shaft member rotating around a rotating axis that has been set with an axial direction along the predetermined direction, while revolving around the revolving axis. The shaft member has protruding sections that protrude outward in a direction that intersects with an axial direction of the shaft member.
