Abstract: An apparatus for recycling a grinding slurry capable of effectively removing unwanted components at a reduced cost. Slurry used in a grinding treatment is at first recovered as recovery slurry. The recovery slurry is then recycled so as to obtain recycled slurry. One or more cyclone separators are provided and used for sizing the used slurry to obtain slurry particles having a predetermined particle size. The slurry having the predetermined particle size is supplied as recovery slurry. When the recovery slurry is recycled to produce recycled slurry, one or more supersonic wave generators are used for irradiating supersonic waves to the recovery slurry.