a method and an apparatus which can manufacture dried foods giving the person who eats the dried foods a soft - dried and spongy feeling pleasant to the palate by evaporating the greater part of the moisture in the raw materials to be removed in as short a time as possible after the commencement of the drying process . according to the present invention , this is achieved by a method for manufacturing dried foods wherein raw food materials are radiated with microwaves under reduced pressure conditions while immersed in oil as well as by an apparatus for manufacturing dried foods comprising an oil tank arranged within a pressure reducing chamber having a pressure reducing device ; a retainer for containing raw food materials immersed in oil in said oil tank ; and a microwave radiating device for radiating said raw food materials with microwave while immersed in the oil .