Dry electrical discharge machining (dry EDM) has characteristics of high work removal rate and low tool electrode wear ratio. Hence dry EDM is suitable for three-dimensional milling of difficult-to-cut materials, such as cemented carbide. We compared machining characteristics between dry EDM milling, oil EDM milling and oil die sinking EDM and found that dry EDM milling is most advantageous to three-dimensional milling of cemented carbide considering the total machining time and cost.