A magnetic disk drive having a magnetic disk, a spindle motor for rotating the
magnetic disk, a magnetic head slider for recording or reproducing data onto or
from the magnetic disk and a housing. A control circuit system is provided for
controlling the head slider so that the head slider is positioned on the magnetic
disk plane when the magnetic disk is rotating, and the head slider is saved to
outside the magnetic disk plane when rotation of the magnetic disk is stopped.
A lubricant supplier is provided for supplying lubricant to the surface of the
magnetic disk. The lubricant supplier contains at least a perfluoropolyether compound
having any one of an alcohol group, a cyclic ether group, and an alkyl-ester group
at its terminal position as a lubricant, and the lubricant contains the perfluoropolyether
compound having a molecular weight sufficient to enable lubrication and no greater
than 4000.
