The invention discloses a device for measuring subsurface structure characteristic and micro-area
wideband dielectric property, and the device comprises an electrostatic force
microscope which comprises a conductive miniature
cantilever probe comprising a conductive probe part and a miniature
cantilever probe part, wherein a probe carries out the first scanning of a to-be-measured sample in a touch scanning mode. The device also comprises a phase-locking
amplifier which is used for receiving a reference frequency
signal and a real-
time signal generated in the first scanning process, and generating a first phase
signal according to the reference frequency
signal and the real-
time signal. After the first scanning, the probe carries out the second scanning of the to-be-measured sample along the scanning trace of the first scanning in a mode of lifted scanning. The phase-locking
amplifier also generates a second phase signal according to the reference frequency signal and a real-
time signal generated in the second scanning process. The device also comprises a
signal source which enables a modulation
voltage signal to be applied to the conductive probe part in the second scanning process, and to be outputted to an external phase-locking
amplifier. The device also comprises the external phase-locking amplifier which is used for receiving the modulation
voltage signal and the second phase signal, and obtaining a
dielectric response signal and a
dielectric loss angle signal according to the modulation
voltage signal and the second phase signal.