Hydrofluoric acid release accident occurred in Gumi industrial area in September of 2012 was analyzed by applying simple modeling Consists of 3 steps; liquid phase release, evaporation into atmosphere, and dispersion. The dispersed distance along crosswind direction was reconstructed through measuring concentration of hydrofluoric acid around the leaves of the scene and Gaussian dispersion modeling was applied to evaluate the amount released. The amount released was calculated by simple equation relating evaporation rate expressed in terms of temperature and material properties. The results will be good example to prepare countermeasures against similar toxic release.