Schemes for in-situ resonant frequency tuning of nano scale vibrating structures using Focused Ion Beam (FIB) sputtering and FIB-Chemical Vapor Deposition (CVD) are presented. This approach introduces precisely controlled permanent increase or decrease of resonant frequencies on processed nano structures, enabling the frequency adjustment when the desired resonant frequency is higher or lower than the actual frequency of the fabricated resonators. The vibration is induced by electrostatic force between resonator and stator using 0-10V AC input and all the processes including fabrication of nanostructure, electrostatic actuation, vibration observation and frequency tuning in either higher or lower direction were successfully conducted in single FIB chamber. The range of the frequency tuned from 600kHz initial resonant frequency is +6kHz with -1.9μm and -65kHz with +1.1μm length change of the nano-resonator respectively. Structural FEM analysis result is compared with the experimental result.