Results from an experimental investigation for diesel soot oxidation strategy using high-frequency electromagnetic waves in producing metal sparks is provided in this paper. It is envisaged that the micro plasma develop by metal when subjected to high-frequency electromagnetic waves, produces heat that enables soot oxidation process. The work attempts to investigate the relationship between spark inception of metals and micro plasma temperatures at different microwaves intensity. Various metal specimens were exposed to high-frequency electromagnetic waves at different power levels at a specific duration of time. The sparks temperatures or micro plasmas produced by the metals were measured using a high-range infrared thermometer. It was found that aluminum and brass have high spark temperatures when compared to mild steel at lower microwaves power levels. However, both aluminum and brass have lower melting point temperatures than mild steel. This makes the material unsuitable for prolong exposure to high-frequency electromagnetic waves. Mild steel was found the suitable metal to be used as the spark inceptor in the soot oxidation reaction chamber. © (2014) Trans Tech Publications, Switzerland.