Abstract: The invention concerns temperature stabilized resonant microwave cavities not requiring hermetic sealing and easy to be frequency adjusted, which essentially consist of a hollow body, a tuning screw, a plug and auxiliary lateral devices for coupling to the diode as well as of a termination, and are characterized in that the hollow body is filled with amorphous quartz. This hollow body consists preferably of an internal thin cartridge or vest made of precious alloy (Invar or Super Invar) forced into the hollow room of a thick support made of less precious material (aluminum).