The design approach that leads to a simple new cavity structure for a microwave discharge used for analytical chemistry is outlined. The design and construction of a totally new and efficient microwave cavity assembly, namely an integrated microwave generator/cavity combination, operated at 2.45 GHz, and preliminary operating conditions that exceed certain operational capabilities of the existing Beenakker and surfatron arrangements are described. The feasibility of operating such a microwave plasma cavity arrangement to form plasma discharges in argon, helium, nitrogen, air and oxygen at atmospheric pressure for atomic emission spectrometry has been demonstrated. The generation of an oxygen microwave induced plasma (MIP) discharge with conventional tubes used routinely in the argon or helium MIP suggests its application in spectrochemical analysis. The introduction of wet aerosols, because of the excellent resistance to detuning caused by changes in plasma density, can be accomplished by using direct solution nebulization with no desolvation system and with a typical inductively coupled plasma nebulizer-spray chamber.