This Research work mainly focuses on optimizing the Electro chemical Machining input parameters like Current, Voltage, Electrolyte Concentration and Inter Electrode Gap applied for micro-drilling operation in a 15-5 PH Stainless steel substrate.Taguchi's L27 orthogonal array and grey relation analysis techniques are deployed for multi -objective optimization in order to maximize the Material Removal Rate and minimize the overcut and Surface roughness. Based on the analysis, it is evident that input current plays a dominant role which affects the output parameters.Finally, the optimum reported values of Material Removal Rate, Overcut and surface roughness are 3.852 g/min , 0.128mm and 1.53µm respectively.