PURPOSE: To provide an automatic positioning method for a grinding wheel which automatically, rapidly, and accurately positions and moves a grinding wheel, on which a dressing work is applied, to the grinding position of a work.

CONSTITUTION: A dresser device 1 for a grinding wheel 6 is fixed on the spindle stock 7 side and an engaging position between the grinding wheel 6 and the dresser device 1, the set position of the grinding wheel 6, and the machining position of a work 10 are always held in a constant state regardless of a dressing work. The X-and Y-coordinates thereof are inputted to a control device, and based on the X-and Y-coordinates, automatic positioning is performed by a control device. This method causes automatic, accurate, and rapid positioning of the grinding wheel after dressing to a machining position without needing the special degree of a skill, improvement of machine working efficiency, execution of high-precise machining, and improvement of productivity.