PURPOSE: To provide simultaneous grinding of shaft and large-diameter cylindrical surface to enhance precision of concentricity and to automate the process by such a construction that a work to be processed is compulsorily rotated by pressing a separately installed rotational driving member against a large-diameter cylindrical surface to be ground other than the reference shaft.

CONSTITUTION: A loading/unloading hook 12 is sunk and the reference shaft A of a work to be processed W is placed on a blade 2. At the same time as completion of the loading, a pressure roller 8 is advanced by driving with a motor 10 until it comes in pressure contact with the large-diameter cylindrical surface of the work W to give to the work W a compulsory rotational force at a certain specific revolving speed. If in this state, a depth feed is given to an adjuster wheel 3 or grinding wheel 5, grindings of the reference shaft A and large-diameter cylindrical surface are started simultaneously. Here the work W is rotated compulsorily by a rotational friction force of the pressure roll 8, so that no slip will be generated between the reference shaft and adjuster wheel even if a friction force exerts between it and the grinding wheel 5.