Monel 400 is a nickel based super alloy containing copper as the main alloying element. Its usage in the industries like marine, aerospace and chemical, makes it an attractive choice for research. It exhibits high strength and excellent corrosion resistance. It is also classified as hard to cut material because of its lower thermal conductivity, higher hardness value and ability to react with cutting tool at higher temperature. High speed micro-milling coupled with different tool coatings was used to analyze machinability of Monel. The surface finish as a result of this study contributes towards the use of this alloy in multiple applications. Key Process parameters including cutting speed, depth of cut, feed rate per tooth and multiple tool coatings were selected as input variables. Effect of these key process parameters on surface roughness was analyzed through statistical analysis of variance (ANOVA). Feed rate having confidence level of 95% was found to be most significant parameter with contribution ratio of 27.86%.