The transparency of thin films of the electroconductive titanium nitride was demonstrated. Titanium nitride has a high hardness and a high resistance against corrosion, and it is electroconductive. Its color is gold, and it is usually not transparent. Materials can be transparent if they are much thinner than the wavelength of visible light. Formerly, there was no technique available to form such a thin TiN film which is also electroconductive, because very thin TiN crystals grow as small islands. However, by using the dynamic ion beam mixing technique, we succeeded in forming continuous, transparent, and conductive TiN films.