To determine whether the short circuit was the cause of the fire or resulted from the fire from the electrical fires is the key point to break through by the researchers of fire investigation even if the observation of cooper microstructure doesn't do it well. Another analytical technique can be used in this research to try to understand the chemical component of the cooper arc bead, it's "Secondary Ion Mass Spectroscopy, SIMS". We want to use its good sensitivity of "Depth Profiling Analysis" to get the sufficient and useful information to determine between the short circuit was the cause of fire or resulted from the fire.