Abstract: The present invention relates to a flag apparatus having a letter or figure displayed thereon, which is formed through weaving or embroidery of an optical fiber and thus can be easily recognized even at nighttime. The flag apparatus includes a supporting pole, a flag suspended from the supporting pole, an optical fiber thread having an exposure part which is formed by exposing a partial area of the upper surface of the flag and is configured in a letter or figure, and a power source module for irradiating light or an image on the optical fiber thread, wherein the power source module includes a light source unit, a power supply unit for supplying electric power to the light source unit, and a control unit for controlling the light source unit and the power supply unit, and the exposure part is configured to be installed on the flag through at least one method among weaving, embroidery, sewing, laminating, and piping.