An abrasive type vertical grain milling machine (4) comprises a perforated cylindrical body (42) which serves to define an outer periphery of a grain milling chamber and which has a plurality of vertically arranged resistance members (53) projected radially into the grain milling chamber so as to impart resistances to motions of the grains in a circumferential direction of an abrasive type roll assembly, an amount of projections of each of the resistance members (53) being made to be adjustable, and further has projection amount adjusting mechanisms (45) for adjusting independently the respective amounts of projection in the radial direction of the plural resistance members (53) located in different vertical positions, and therefore, it is possible to adjust independently the resistance imparted to the motions of the grains within the grain milling chamber in each of the upstream-side region and downstream-side region of the grain milling chamber.