A vibrating gyroscope consisting of three layers of polysilicon thin films has been developed. It has an upper electrode over a resonating mass for detecting the sensing vibration oscillated by the Coriolis force accurately. The resonant frequency of both driving and sensing vibration is successfully controlled by the DC bias to comb electrodes that are used for detecting the driving vibration. The offset on the angular rate output due to the mechanical and electromechanical couplings is decreased by an unbalanced differential oscillation. With this tuning method and the offset reduction, the angular rate was detected. The resolution of 1 deg/sec is achieved.