To detect near-field light, which is generated by a thermal assist type magnetic head element, and leaking light with high sensitivity and to more accurately obtain the spatial intensity distribution of a near-field light generation area, an inspection apparatus for a thermal assist type magnetic head element is adapted so that a distance between a cantilever and the surface of a specimen and the excitation amplitude of the cantilever are set to be small to detect near-field light with high sensitivity by the suppression of an influence of other light components, a distance between the cantilever and the surface of the specimen and the excitation amplitude of the cantilever are set to be large to detect other light components present in the vicinity of near-field light with high sensitivity by the suppression of an influence of the amount of detected near-field light when other light components are measured.