The present invention is provided to remove scattering from other parts, except for an end part of a nano-probe, in a near-field microscope, and to enable a spectral analysis by delaying the generation of multiple reflections caused through the shaft of the nano-probe. A first characteristic of the present invention is to temporally delay generation of multiple reflections by manufacturing a probe portion to have a predetermined length or more in a tuning-fork based near-field probe. A second characteristic of the present invention is to provide a near-field microscope which includes a tuning-fork based near-field probe having a structure as above, and can measure a time-domain transient reaction of a scattered wave. A third characteristic of the present invention is to provide a method for performing a spectral analysis on a time-domain signal measured by the near-field microscope.