The objective of the present invention is to provide a method for manufacturing a freeze-dried body and a manufacturing device for the same, with which energy saving, cost reduction and a reduction inprocessing time are achieved, in addition to which damage resulting from a freezing process and a drying process is suppressed. The freeze drying method in which an object is freeze dried using electromagnetic waves is characterized in including: a freezing step for freezing the object in an environment in which at least electromagnetic waves are applied; and a reduced-pressure drying step for drying the frozen object under reduced pressure in an environment in which at least electromagnetic waves are applied.