Abstract: A modular microwave processing system includes a microwave source, a transmission line, and a detachable processing cavity or chamber. The chamber is adapted to maintain a controlled atmosphere surrounding a workpiece, and further contains an interface to engage the microwave transmission line so that power for heating the workpiece is introduced through the interface. The system is particularly suited for remote operation and for processing hazardous or accountable materials. It may also be adapted for operation in a hot cell or other controlled area while locating the microwave power source outside of the controlled area for ease of maintenance.