Most mechanical parts like bearings, gears, and shafts are produced by finishing processes such as hard turning, grinding and/or honing. The durability and reliability of these precision products are directly influenced by mechanical behavior of material. If those parts are in micro nano scale such as micro interconnector, micro valve, micro actuator, and micro switch in that case micro nano mechanical properties is an important factor for better performance. This present paper discusses the low energy ECR ion beam irradiation effects on mechanical property of material in micronano scale. To complete this research ion beams were irradiated for different accelerating energy to Si surface. Nano indentations were done for hardness and elasticity measurement. AFM was used for roughness and depth measurement. From data analysis It shows accelerating energy is an important factor to control mechanical property of material during nano scale fabrication by ion beam.