To provide a technique that allows a work piece to be efficiently ground to reduce processing time.

The grinding device 1, which grinds the surface of a work piece W by rotating and contacting a grind stone 2 and the work piece W, comprises: a feed drive 53 that relatively moves reciprocatingly the grind stone 2 and the work piece W; and a control device 6 that feeds relatively the grind stone 2 toward the work piece W at a first predetermined speed to contact the grind stone 2 with the work piece W, then increases the first speed to a second speed faster than the first speed, relatively feeds the grind stone 2 toward the work piece W at the second speed, and after decreasing the second speed to a third speed, controls the feed drive 53 to relatively feed the grind stone 2 toward the work piece W at the third speed until the position of the surface of the work piece W reaches a position at which the third speed is switched to a finishing speed.