A scanning probe microscope has a probe tip for undergoing a scanning
operation to scan a sample surface in X- and Y-directions parallel to the
sample surface and for undergoing movement in a Z-direction vertical to
the sample surface. A vibration unit vibrates the probe tip at a
vibration frequency that resonates with of forcedly vibrates the probe
tip. An observation unit collects observational data from the sample
surface when the probe tip is in proximity or contact with the sample
surface. A detection unit detects a variation in the state of vibration
of the probe tip when the probe tip is in proximity or contact with the
sample surface during a scanning operation. A control controls scanning
of the probe tip in the X- and Y-directions and movement of the probe tip
in the Z-direction, and controls scanning of the probe tip in a direction
parallel to the sample surface after the observational data is collected
from the sample surface and until the probe tip reached a next
observation position in the X- and Y-direction. During a scanning
operation, the control unit controls the probe tip to move in the
Z-direction away from the sample surface only when the detection unit
detects a variation in the state of vibration of the probe tip.