Patent ID: 8151368

Claim:
A dynamic mode AFM apparatus comprising: (a) a scanner for performing three-dimensional relative scanning of a cantilever and a sample; (b) a means for generating an AC signal of a resonance frequency in a mode with flexural vibration of the cantilever; (c) a means for exciting the flexural vibration of the cantilever with the resonance frequency; (d) a means for generating an AC signal of a second frequency which is lower than the frequency of the flexural vibration; (e) a means for modulating a probe-sample distance of the cantilever with the second frequency; (f) a means for detecting fluctuation of the resonance frequency; (g) a means for detecting vibration of the cantilever; and (h) a means for detecting a fluctuation component which is contained in a detected signal by the means for detecting the resonance frequency fluctuation and synchronized with a modulation signal of the probe-sample distance, (i) wherein an inclination of the resonance frequency against the probe-sample distance is obtained from strength and polarity of the fluctuation component.