Patent ID: 8615811

Claim:
A method of measuring vibration characteristics of a cantilever in a scanning probe microscope (SPM), the scanning probe microscope including: the cantilever; a vibrator portion for vibrating the cantilever; an excitation signal generator for supplying an excitation signal to the vibrator portion; a displacement detector for detecting a displacement of the cantilever; an AC to DC conversion mechanism for converting an AC signal indicating an amplitude of the displacement output from the displacement detector into a DC level signal; and a frequency vibration characteristics detection mechanism for measuring the amplitude of the displacement of the cantilever with respect to an excitation frequency, the method comprising: generating a forward and backward frequency sweep signal from the excitation signal generator in a frequency range including a resonance frequency of the cantilever; vibrating the cantilever by the vibrator portion; directly measuring the largest amplitude of the displacement of the cantilever in a forward path and in a backward path; and detecting as the resonance frequency of the cantilever an intermediate value of a frequency between frequencies measured on the basis of the directly measured largest amplitude of the displacement of the cantilever.