To improve dry controlling accuracy by improving the accuracy of detecting the set-in position of grain to accurately determine the set-in amount of the grain.

This device for detecting the amount of grain set in a grain storage chamber comprises a grain detecting sensor B provided in the grain storage chamber 3, which consists of a plurality of first electrode part 20 arranged at set spaces in the vertical direction and second electrode part 21 connected between the opposed first electrode parts 20 and each having a grain abutting area smaller than the first electrode part 20. The grain detecting sensor B for detecting the change amount of capacitance for every set time during setting the grain in the grain storage chamber 3. From the change amount of the capacitance, a control part determines whether the set-in position of the grain is in the position of the first electrode part 20 or in the position of the second electrode part. When detecting that there is no change amount of the capacitance, it determines that the detection position is the set-in position of the grain.