For clearing the cause of firing due to the tacking on the surface of phenolic resin, this paper describes the analysis through a couple of methods ; FT-IR; DTA; photograph analysis, etc. Phenolic resin has been widely employed as a case of low voltage appliances. In the experiment it was confirmed that its surface was carbonized and graphitized by the external fire. In the FT-IR test a graphite specimen thermally treated at $150[^{circ}C]$ showed the 2 different IR absorption peaks at $1,730[cm^{-1}];and;1,680[cm^{-1}]$. In normal phenolic resin, the exothermic peak appeared at $450[^{circ}C]$, while in graphite specimen, it appeared at $610[^{circ}C]$ in DTA test. From the results, the electrical fire causes could be cleared and it is expected to protect the human life and property from the electrical fire by using the important data.