film of hard magnetic material effective to maintain the magnetization direction of the probe constant and parallel to the given magnetization direction of the sample application_number US 55937600 A description next examples of the present invention will be explained below on the basis of the drawings attached hereto fig1 is a perspective view showing a cantilever magnetic force sensor of the present invention to be used in magnetic force microscopy a stainless steel foil 1 was machined into the form of a leaf spring as shown in fig1 and a probe 3 was fitted onto the tip of the leaf spring 2 for resiliently biasing the probe 3 in response to a magnetic force between the probe and a sample to be measured fig2 is a graphical view showing the enlarged cross section of the tip of the probe of the cantilever of the present invention to be used in magnetic force microscopy a thin film 5 of an iron cobalt alloy was plated by electrolytic plating onto the surface of an iron probe 4 that had been machined to have a needle like shape by electrolytic abrasion fig3 is a graphical view showing the motion of the iron cobalt alloy probe of the present invention in the measurement of a magnetic force of a sample by means of microscopy using the probe the sample to be measured is a vertical magnetic recording medium in fig3 the magnetizing direction of the sample and that of the probe are represented by arrows u2192 and the distribution of.