Abstract: The present invention relates to a photocatalyst toothbrush using an AOP (advanced oxidation process) which is configured such that a light source unit 113 such as UV lamps is attached to a photocatalyst reaction unit 114 coated with a photocatalyst such as TiO2, superoxide anion and OH radical are generated by a photocatalyst action, and the generated superoxide anion and OH radical are collected and are transferred together with external air to an oral cavity by using an air pump 115. In this way, organic substances, such as food, viruses, bacteria, plaque, tartar, etc., existing in the oral cavity are decomposed and removed so as to provide a clean oral-cavity state. Since the exemplary embodiment of the present invention is innovative in the generation and transfer configuration of anion and OH radical and has a simple configuration, the manufacturing is easy.