Abstract: An air cleaning device for a magnetic disk drive and capable of removing oil mist ascribable to grease which is applied to the bearings of a head positioning mechanism. A passageway is provided between an area generally defined by the neighborhood of the disks and a second area generally defined by the vicinity of the head positioning mechanism. Pressure differential is generated within the passageway upon rotation of the disk. The pressure differential causes air to flow from the second area, through the passageway, and into the first area. A filter captures oil mist entrained by the flowing air.