Abstract: A microwave waveguide switch assembly comprises a stationary housing having four openings and a cylindrical chamber of housing rotor which has a microwave switch section formed with two cylindrical axially spaced plates at ends of an integral bar to contain the microwave energy between the walls of the rotor and the chamber wall during transmission of microwave energy through selected passages in the housing. The plates and the bar along with the chamber wall provide an essentially sealed microwave passageway thus minimizing transmission losses and at the same time, preventing leakage of microwave energy between passageways.