A scanning probe microscope in which the deflection of a cantilever (1, 104) caused by the proximity between a stylus (17, 109) and a sample (2) is detected, the relative distance between the sample and a probe at which the level of the deflection detection signal coincides with a reference level is subjected to servo control thereby to control the force exerted on the stylus to a constant level, and the relative positions of the sample and the probe are scanned to produce a three-dimensional image of the surface of the sample. In order to eliminate the error of servo control attributable to the deformation of the cantilever, the deflection detection signal is held with the cantilever set in free standing state, and the signal thus held is used to correct the level of the cantilever deflection detection signal. The servo control is effected by the detection signal thus corrected.