In this study, we demonstrate a feasible route to fabricate fully transparent thermoelectric devices using solution-processable oxide nanomaterials. Our thermoelectric device is constructed with electrospun ZnO nanofibers and ITO nanoparticle electrodes. The transparency is comparable to that of bare glass when it is viewed with the naked eye, and the transmittance is above 85% in the visible wavelength range. The thermoelectric characteristics are examined in air at room temperature. The maximum Seebeck voltage is -320 mu V at a temperature difference of 2.3 K, and the Seebeck coefficient is -135 mu V/K.