Microwave oven with a vertically translatable resistance heater or the like

摘要

A microwave oven having a vertically translatable resistance heater disposed in the heating chamber thereof is disclosed. The two end portions of the heater extend from the interior of the heating chamber to the exterior thereof through a pair of parallel vertically elongated openings. The heater is vertically translated by a translation mechanism along the two elongated openings. The leakage of the electromagnetic waves through the elongated openings is prevented for the most part by annular choke chambers which are situated around the elongated openings and have communication ports which oppose the extending portions of the heater and through which electromagnetic waves leaking from the interior of the heating chamber through the elongated openings are introduced, thereby extinguishing the electromagnetic waves leaking through the elongated openings. Other auxiliary devices for preventing the leakage of the electromagnetic waves, such as absorbers, attenuators, or further choke chambers, may also be used together with the above noted choke chambers.