An apparatus which presents a mechanical milling with electric discharge is introduced. As a model experiment, an anatase TiO2 nanopowder was processed by the method using NH3(10%)/N2 gas. The influences of specific surface area, crystal structure, and optical property were investigated. Relatively high specific surface areas exceeding 250m2/g were observed for all processed powders. The crystal structure and crystallinity of TiO2 did not change by the milling with electric discharge. On the other hand, noticeable absorption in Vis light range was observed, suggesting nitrogen doping into the powder.