Abstract: In present scenario, high speed steel tools are more popular because of their good toughness at high hardness, high wear resistance, and relatively high abrasion resistance properties. High speed steel is widely used to manufacture various cutting tools like tool bits, taps, milling cutters, drilling tools, planer tools and saw blades etc. So that, High Speed Steel, is selected as a workpiece material. In this paper, the behavior of an, high speed steel has been studied using electrical discharge machining (EDM). The response parameters selected are the material removal rate (MRR) and the surface roughness (SR). All of them have been studied in terms of current intensity supplied by the generator (I), voltage (V) and pulse time (Ton). To carry out the experiments, design of experiment (DOE) techniques have been used in order to obtain mathematical models to predict the most influential factors by using a small number of experiments. The experimental results confirm that positive polarity leads to higher MRR.