The present invention is directed to setting an operation parameter of a grain milling machine appropriately according to the characteristics of grain targeted for processing. An operation aid apparatus for a grain milling facility including a grain milling machine and a color sorter includes a first acquisition portion configured to acquire first information regarding characteristics of grain that should be processed in the grain milling facility, and a second acquisition portion configured to acquire second information regarding an evaluation of a sorting result acquired by milling first grain by the grain milling machine and sorting them by the color sorter after that. The second information is associated with the first information regarding the first grain. The operation aid apparatus further includes a setting portion configured to determine an operation parameter for processing second grain by the grain milling machine based on the first information regarding the second grain that should be newly processed in the grain milling facility and the second information associated with the first information regarding the first grain.