PURPOSE: To facilitate control of the contact position of a grinding wheel with a work, by providing grooves in the circumferential portion of a grinding wheel directly coupled with a rotatably driven motor and applying a interchangeable grinding belt to the periphery of the wheel in such a way that some portions of the grinding belt are turned into the grooves so as to be stretched and fixed.

CONSTITUTION: A grinding belt 2 is applied to a nonconsumable wheel 1 at its periphery and grooves 5, and the belt is stretched and fixed by means of belt pushing pins 3 and a tension metalware 4. Through grinding work, the grinding belt 2 wears off but more slowly than an ordinary grindstone, and therefore control of its contact position with a work to be carried out by a robot, etc. is facilitated. Since the consumable is only the grinding belt 2, cost reduction is attained, and since only one wheel is used, the weight to be carried and moved by a robot, etc. is made smaller.