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.