An abrasive type vertical grain milling machine in which each of spacers comprises a boss portion fitted on a main shaft and a plurality of arm portions extending from the boss portion in the radially outwardly and serving to induce bran removing air into a grain milling chamber through spaces between the circumferentially adjacent arm portions, is capable of discharging bran produced in the grain milling chamber with high bran discharging power and has little possibility that the bran removing power is reduced during operation.