Monel 400 is a cuprous nickel alloy which is very well-known for its resistivity towards physical and chemical strength. It is probably one of the hardest and most non-corrosive materials known in industrial as well as research field. These properties have enhanced its applications in various fields such as aerospace industries, marine industries, automotive industries etc. Monel 400 alloys are too hard to machine using conventional machine tools and methods as it work hardens rapidly on its surface. Authors concluded that electrochemical machining is the choice of machining of these materials. The present work is carried out to analyze the impact of ECM process parameters such as applied voltage (V), inter-electrode gap (IEG) and electrolyte concentration (EC) on material removal rate (MRR) and surface roughness (Ra). An aqueous sodium nitrate (NaNO3) is used as basic electrolyte in the electrochemical machining of Monel 400 alloys. Response surface methodology (RSM) based central composite design (CCD) is used as experimental strategy. Effects of process parameters as well as their interactions are analysed and the process parameters are optimized.