To accurately measure a moisture value of the whole charged grain in a circulation type grain drier.

This circulation type grain drier for drying grain while circulating the same through a storage chamber 2, a drying chamber 3 and a grain collecting chamber 4, is provided with grain charging quantity setting means SE6, SE9 for setting the grain charging quantity to the grain drier, and the whole charged grain in the drying chamber 3 is fed out while performing drying work by operating a feed valve 10 by every prescribed time while separating the same into a plurality of drying blocks. Further a block grain moisture value measuring means 41, SE5 for taking out sample grain and measuring its moisture value is disposed on the way of circulation of the dried grain fed out from the drying chamber 3 to the storage chamber 4, and the measured dispersion maximum moisture value and dispersion minimum moisture value and an average moisture value of the block dried grain are displayed on a display portion 32.