This paper presents the structural analysis and optimum design of a vertical micro-gyroscope with decoupled 2 degrees of freedom (DOF), driven by electrostatic force. Simplified beam models were presented to derive the structural stiffness of the driving spring of the U shape and the sensing spring of I shape. A finite element analysis (FEA) was performed to validate each derivation. A total mass and a polar mass moment of inertia were also obtained and used in calculating the resonance frequency at each mode of the 2 DOF. The resonance frequencies of the total system were calculated using the proposed models and it has been found that they were in excellent agreement with those of the FEA. Finally, the developed analysis program was then linked to an optimum design module, and an optimum design of the micro-gyroscope was successfully performed.