A centrifuge for cleaning the lubricating oil of an internal combustion engine, which simultaneously cleans the crankcase gases in which the separation result is improved by introducing crankcase gases (dashed arrows) directly, without any shielding baffles, into the oil mist generated by the drive nozzles in the centrifuge housing in order to produce a scrubbing effect, so that the crankcase gases are precleaned. For additional cleaning, guide vanes mounted on the rotor swirl the crankcase gas so that further residues are deposited along the walls of the housing, thereby making further measures to clean the crankcase gases unnecessary, with the result that the apparatus highly economical since it saves both material costs and maintenance costs.