PURPOSE: To enhance utilizing efficiency of heat by constituting the dryer of both an independent type drying unit wherein the respective drying heating sources are independently provided to the respective drying chambers of a sample of grain and an assembled-type drying unit wherein the respective drying chambers of the sample of grain are connected to a common drying heating source.

CONSTITUTION: The dryer of a sample of grain is constituted of both an independent type drying unit A wherein the respective drying heating sources are independently provided to a plurality of respective drying chambers 1 for drying the sample of grain and an assembled-type drying unit B wherein a plurality of respective drying chambers 3 for drying the sample of grain are connected to a common drying heating source. As a result, the drying heating source and an object to be controlled can be drastically reduced as a whole. Therefore the utilizing efficiency of heat is enhanced and operating cost can be reduced and operation control can be made easy.