This paper deals with EDM characteristics of newly develops electrically conductive ceramics. Titanium boride (TiB2) is widely used as die and mold materials because of its high hardness, high-temperature resistance and so on. The EDM characteristics of the titanium boride, such as electrode wear rate, removal rate and surface roughness were investigated. Experimental results show that EDM with low electrode wear rate is possible when copper electrode is used with positive polarity. The removal rate becomes much higher when graphite electrode is used with negative polarity.