Precision cleanings of stainless steel plates covered with press working oil by using ozone microbubble(bubble size: Ca. 2-50 μm) combined with sonication(42KHz, 40W) were investigated in water. Oil removal efficiencies of the sample plates were investigated by using a microscope, FT-IR and a waterdrop contact angle measurering apparatus. From experimental results, effective removals of press working oil from the surfaces of the sample plates by the investigated cleaning mehod were shown to be achieved.