To realize oil separation with good efficiency by reducing a ratio of the oil remaining in a powdery substance discharged from a cyclone in an oil separation apparatus.

The subject remaining oil removal device is constituted such that air is fed to the powdery substance 100 discharged from the cyclone 7 using a blower 73 and the remaining oil is ignited to scatter the oil. At this time, a rotary valve 72 is mounted between a discharge port of the cyclone 7 and a storage part 71 such that ignition of the oil at the storage part 71 is not transmitted into the cyclone 7.