To eliminate only grinding wheel bond and to adjust the ejecting amount of a grinding wheel.

This device is provided with a laser oscillator 1 for projecting laser light rays 2, a laser controller 6 for controlling the laser oscillator and adjusting projected energy/projecting number/projecting time, an optical system, such as a mirror 3, for irradiating a grinding wheel surface with the laser light rays 2, a motor 5 for rotating a grinding wheel 4, a motor controller 7 for controlling the motor 5 and a comprehensive controller 8 for controlling the laser controller 6 and the motor controller 7. Thus, the ejecting amount of abrasive grains is adjusted in a submicron order. Thus, the state of the surface of a workpiece to be ground is adjusted. Also, since machining is based on optical chemical reaction, even if uneven parts exist as in the case of a form milling grinding wheel, the ejecting amount of abrasive grains similar along the form is obtained.