A scanning probe microscope has a cantilever having a minute probe on a distal end thereof and a displacement detecting device for detecting displacement of the cantilever. A Z-axis controlling amount calculating mechanism calculates a controlling amount for keeping constant a displacement amount of the cantilever. A Z-axis driving mechanism drives in a Z direction the cantilever or a sample in accordance with the controlling amount from the Z-axis controlling amount calculating mechanism. An XY scanning mechanism relatively moves the probe in a direction of an XY plane with respect to the sample to measure an uneven shape and/or a physical characteristic of the surface of the sample. A controlling range limiting device limits a driving range of the Z-axis driving mechanism. A controlling range setting device optionally sets the driving range of the Z-axis driving mechanism.