Abstract: A computer diskette burnishing machine that consists of two burnishing units adapted to operate on the magnetic medium of a conventional computer disk through the upper and lower read/write head access windows in the disk's protective shell. The assembled diskette is positioned on a lower burnishing unit that comprises a supporting plate having the same mechanical characteristics of a corresponding computer disk drive, including an electric motor equipped with a spindle/hub interface and shell registration pins. While the disk rotates, the burnishing units polish the disk's upper and lower surfaces by means of upper and lower abrasive tapes fed by a system of supply and take-up reels. The lower burnishing unit includes a resilient roller backing up the lower abrasive tape and disposed radially with respect to the plane of the disk. The upper burnishing unit consists of a spring-loaded resilient roller backing up the upper abrasive tape and disposed radially in parallel to the lower roller.