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.