Abstract: This invention relates to an apparatus, namely a continuous microwave and vacuum dryer, useful for evaporating a liquid from a liquid containing material by means of microwave and vacuum.This apparatus, especially suitable for continuous dehydration of foodstuffs, comprises a housing forming a closed elongated space, means for evacuating said closed space, means for partitioning the closed space into two chambers which communicate through a slit provided in the partition, a conveyor belt disposed longitudinally in the two chambers, means for feeding on the conveyor belt a material to be evaporated, at least one source of microwave energy fed into the first one of the two chambers by at least one adjustable microwave cavity at atmospheric pressure through an air tight membrane provided on the first chamber.