Magnetic force microscope (MFM) tips are prepared by coating Si tips of 3 nm radius with 20-nm-thick Fe100−xBx (x = 0, 8, 18, and 34 at. %) alloys. As the B composition increases, the wettability of Fe-B alloy material to Si surface increases and a sharper and smoother MFM tip is obtained. The remanent magnetization of Fe-B alloy material decreases with increasing the B composition, which degrades the MFM signal detection sensitivity. The MFM resolution is influenced by both the tip sharpness and the remanent magnetization of coated Fe-B alloy material. Resolutions of 10.2, 9.2, 7.3, and 9.3 nm are obtained with tips coated with Fe, Fe92B8, Fe82B18, and Fe66B34 materials, respectively. Magnetic bits of 14.9 nm in length of a perpendicular magnetic medium recorded at 1700 kfci are distinguishable in the MFM image observed by using an Fe82B18-alloy coated tip. Fe-B coated tips are suitable to observe the magnetization structures of future high-density recording media.