Numerical studies of subsonic gas flow through micro-thruster as no-slip benchmark problem and high speed gas flow through short micro-channel with slip and temperature jump correction have been carried out by solving two dimensional compressible Navier-Stokes (NS) system of equations. A 2-D explicit finite volume (FV) flow solver has been developed using modified advection upwind splitting methods (AUSM+) to achieve the solution of micro-scale gas flow having high resolution shock capturing ability. The results obtained are compared with published 1-D numerical, Direct Simulation Monte Carlo (DSMC) and 2-D Finite element (FEM) results. This study utilizes the robustness and accuracy of AUSM+ and FVM to predict the micro-scale gas flows with simple explicit time marching, ranging from subsonic to supersonic flow.