A method is for dividing a plate-like workpiece in which devices are respectively formed in regions sectioned by a plurality of intersecting planned dividing lines. The method includes: forming a first cutting groove not reaching a rear surface of a workpiece by causing a rotating cutting blade to cut into from a front surface of the workpiece along the planned dividing lines; after forming the first cutting groove, forming a second cutting groove not reaching a bottom portion of the first cutting groove by causing the rotating cutting blade to cut into from the rear surface of the workpiece along the first cutting groove; and after forming the second cutting groove, dividing the workpiece along the planned dividing lines by applying external force to the workpiece.