In this paper, an attempt was made for enhancing the micromachining characteristics of Hastelloy C276. For drilling holes in the Hastelloy, Copper Nano powder assisted electrochemical micromachining process was used. By fluctuating important electro chemical machining process parameters such as concentration of NaBr electrolyte, machining voltage and concentration of Cu Nano powder, holes were drilled. Using central composite design model, twenty different drilling experiments were conducted. Relationships were developed to establish relationship between the electro chemical drilling process parameters and output responses such as material removal rate and overcut at the interior side. Using analysis of variance, the significance of the developed model was ascertained to a high level of certainty. Using response surface methodology, the micromachining process parameters were optimized. At optimized concentration of Na Br electrolyte of 11.2 g/l, machining voltage of 7.4 V, Cu concentration of3.3 g, highest material removal rate of 0.000196622 and least entry side overcut of 0.208768. As the error obtained in validation experiments were lesser than 4% the optimization model was found to be developed with high predictability. The variations in the hole edges were evaluated by using scanning electron microscopy.