In this study, the machining characteristics of AISI 202 stainless steel have been investigated in thermal erosion process. Taguchi method based experiments have been conducted with conventional and modified pulse generators using electric discharge machining. Material removal rate (MRR) and surface roughness were taken to evaluate performance of process. Gap voltage, discharge current, and duty factor have been chosen as input parameters to access the machinability. The efficacy of pulse generators in thermal erosion process is determined by high material removing property and better surface finish. Since this machining process has stochastic nature, conventional RC relaxation pulse generator and transistor pulse train generator could not satisfy both the two requirements. It is proved that modified ISO current pulse generator could produce better surface finish with high MRR than conventional pulse generators in thermal erosion process.