Method for drying under reduced pressure using microwaves

A method for drying under reduced pressure using microwaves, comprising:

• placing an object in a chamber connected to a depressurizing pump;
• and
• irradiating the microwaves to the object while maintaining an inside of the chamber under reduced pressure, wherein
• a) the inside of the chamber is depressurized to or below a saturated vapor pressure corresponding to a deterioration temperature of the object;
• b) a gas is supplied from an outside to the inside of the chamber;
• c) the object is dried while a temperature of the object is maintained below the deterioration temperature of the object by intermittent irradiation of the microwaves;
• and
• d) the gas is supplied from the outside to the inside of the chamber while the inside of the chamber is maintained under reduced pressure and an airflow is generated around the object, and
• wherein water evaporated from the object and the gas are discharged out of the chamber as an exhaust gas by the depressurizing pump to promote dehydration of the object, and
• the intermittent irradiation of the microwaves is controlled in a manner that the irradiation of the microwaves is stopped when the temperature of the object increases to a specific temperature “A”, and subsequently, the irradiation of the microwaves is resumed when the temperature of the object lowers to a specific temperature “B”, the specific temperature “A” being below the deterioration temperature of the object, the specific temperature “B” being in a vicinity of or higher than a saturation temperature corresponding to a pressure in the chamber.