To provide a grinding device having a simple structure capable of providing a uniform grinding surface over the whole area of a work.

This device is provided with a reciprocating shift mechanism (a motor) for reciprocating and shifting a grinding wheel (a honing head) rotated and driven by a rotational driving mechanism (a motor) along with its rotary shaft, and a rotation speed control means (a control unit) for decelerating and controlling rotation speed Vθ of the grinding wheel according to a change of shift speed Vh of the grinding wheel at the vicinity of a turning point of the reciprocated and shifted grinding wheel. Relationship between the reciprocating shift speed and the rotation speed (peripheral speed) of the grinding wheel is kept almost constant by decelerating and controlling the rotation speed (the peripheral speed) so as to watch the shifting speed of the grinding wheel, thereby, an intersecting angle of a crosshatch line is fixed over the whole area of the work.