Material will be spread onto pedrail uniformly. When it passes through the first region, it is acted by microwave. Its energy will turn to heat energy at instantaneous and make material begin to raise its temperature from intesrior to exterior, water vapor pressure of granule interior layer is raised suddenly and forced water vapor to expand towards exterior layer of granule. At this time material will be transmitted to second region, plenty of hot air that is heated by compensation or cycle will enter into box and carry damp air to exhaust out. After enter into third region, part of moisture has been evaporated and the temperature of material has dropped. If acted by microwave again, the temperature of material will raise quickly. Moisture will be removed by air hole. Move in cycles this way, moisture will be dropped and the purpose of dry is reached.