A microwave resonator accelerometer including a microwave resonant cavity having a predetermined resonant frequency; the cavity including a flexible portion; a proof mass fixed to the flexible portion for changing the geometry and establishing a new resonant frequency of the cavity in response to an acceleration force on the proof mass; a microwave frequency signal at or approximately at the predetermined resonant frequency coupled to the cavity; and a discrimination circuit, responsive to the reflected microwave signal from the cavity, for discriminating a shift in the predetermined resonant frequency of the cavity to a new resonant frequency effected by the change in geometry of the cavity resulting from the acceleration force on the proof mass.