To provide a circulation type grain drier capable of detecting a moisture value of every grain layer and drying the grain while equalizing the dispersion of moisture values by mixing upper and lower grain layers.

In this grain drier where grain is circulated through a storage chamber 2, a drying chamber 3 and a grain collecting chamber 4, the drying chamber 3 is provided with a plurality of right and left grain flow-down passages 9, feed-out valves 10 for feeding out the grain are respectively disposed at lower portions of the plurality of right and left grain flow-down passages 9, a moisture detecting means SE5 is disposed for detecting the moisture value of the grain during circulation, the charged dry grain is divided into the plurality of grain layers LV1-LV10, and a representative moisture value of each of grain layers LV1-LV10 is detected by a control portion 41, wherein the plurality of feed-out valves 10, 10 are rotated and driven at different speeds when a dispersion state of the representative moisture values of the grain layers LV1-LV10 is determined to be outside of a set range.