A novel scanning near-field thermoelectric microscopy (STeM) was proposed and developed for characterizing subsurface, nanoscale Seebeck coefficient of thermoelectric energy materials. In STeM, near-field evanescent thermal wave was induced around the thermal probe's contact with the thermoelectric sample's surface via a periodically modulated heated thermal probe, giving rise to a thermoelectric near-field interaction with simultaneous excitation of three harmonic signals for local Seebeck coefficient derivation. The near-field STeM was capable of characterizing local Seebeck coefficient of thermoelectric materials with high lateral resolution at nanometer scale and more importantly provides a convenient, powerful tool for quantitative characterization of subsurface nanoscale thermoelectric properties.