PURPOSE: To obtain an automatic grinding wheel change device which can exchange grinding wheels safely and in a good workablility.

CONSTITUTION: An arm 01 movable laterally, vertically, and longitudinally; a grinding wheel exchange head 1 and a grinding wheel flange bolt change head 4 installed to the arm 01 so that whose base ends can rotate around a horizontal shaft 5 and rotate around a vertical shaft; a grinding wheel flange bolt hole detecting means installed to the grinding wheel flange bolt exchange head 4; and an NC control device to operate the arm the grinding wheel change head, and the grinding wheel flange bolt change head; are provided.