To improve the performance of the Electric discharge machining (EDM) process it is of interest to characterize the plasma involved. Plasma temperature needs to be measured as an initial phase of plasma characterization. Non-contact optical emission spectroscopy has been used to measure the plasma temperature. The plasma temperature and crater morphology has been investigated for different energy conditions on Silicon in dry μ-EDM condition. The plasma temperature is calculated using line pair method and crater morphology analyzed by scanning electron microscope (SEM) and profilometer. © (2011) Trans Tech Publications, Switzerland.