We report on the discharge gas of the electric discharge machining (EDM) for silicon carbide (SiC) single crystal. We investigated the cutting speed and the kerf loss of EDM for SiC by using three kinds discharge gases: Ar, Ar+CH4(10%) and Ar+CF4(10%). The maximum cutting speed of EDM in Ar, Ar+CH4(10%) and Ar+CF4(10%) was 0.02mm/min, 0.04 mm/min and 0.06 mm/min, respectively. The kerf loss of EDM in Ar, Ar+CH4(10%) and Ar+CF4(10%) was 490m, 430m and 470m, respectively. It is shown that cutting with a smooth edge and low kerf loss is faster by mixing CH4 or CF4 in Ar.