An equipment status monitoring system and method of operating thereof is described. The equipment status monitoring system includes at least one microwave mirror in a plasma processing chamber forming a multi-modal resonator. A power source is coupled to a mirror and configured to produce an excitation signal extending along an axis generally perpendicular to a substrate. A detector is coupled to a mirror and configured to measure an excitation signal. A control system is connected to the detector that compares a measured excitation signal to a normal excitation signal in order to determine a status of the material processing equipment.