Finite element analysis showed that strong magnetic fields were distributed around the arc furnace where the strongest magnetic field was generated around the three phase cables, and followed by the electrodes and the mast arm in decreasing order. Magnetic field decay patterns around the arc furnace could be fitted by introducing exponential formula,$Y=Y_0+Ae^{frac-{x}{t}}$. These results showed that magnetic field intensities around the arc furnace could be estimated at any 3-dimensional positions using the finite element method (FEM).