Silicon (Si) wafers are primary substrate materials in the microelectronic and microelectromechanical area because of its superior properties, which can be adjusted. In this chapter, we first provide an overview of the electrical discharge machining techniques. In addition, the capability and performance results of electrical discharge machining techniques for machining three-dimensional cavities on Si with optimum parameter settings are also discussed. The machining performance results of Si with two-different resistivities are discussed using a die-sinking micro-electrical discharge machining technique while varying discharge energy parameters. Moreover, a novel heat-assisted micro-electrical discharge machine technique is performed for machining Si without any conductive layer involved. The machining performance results are presented and discussed in terms of material removal rate, surface quality and materials characterization. Finally, the chapter concludes by discussing the main outcomes of the machining performance.