This note presents the principle and structure of a tribological measure for floppy disks. The precision of the force measuring system is 1 mN in loading and 3×10⁻⁶ N in friction. The resolution of the film thickness between head and floppy disk is 0.5 nm in the vertical and 1.5 nm in the horizontal direction. In order to investigate the tribological characteristics of floppy disks, six types of floppy disks have been tested and the floating properties of these disks are also studied with film measuring system. The experimental results of the surface morphology and friction coefficient of these floppy disks using the atomic force microscope/friction force mcroscope (AFM/FFM) are in accordance with the conclusion made by our own measuring system. The experimental results show that the air film thickness between head and disk is of the same order as the surface roughness of floppy disks.