In each contact material (Ag, Cu, Ni, and Fe), the breaking arcs occurring between an electrical contact pair in a resistive circuit of DC42 V/10.5 A were observed with a high-speed camera (1000 frames/s). Arc voltage and arc current were also measured simultaneously. By analyzing cathode and anode bright spots in the photographs, the positions of cathode and anode bright spots on contact surfaces were plotted on the graph. As a result, cathode and anode bright spots were found to express the characteristic motion in each material. Moreover, by comparing those results with the photograph of contact surface after all operations.