To provide a cutting device improving cleaning function of a workpiece and of achieving improvement of processing quality.

The cutting device includes a cutting blade for cutting the workpiece held at a chuck table. When the cutting blade is sandwiched by a flange and a nut, the outer circumferential part of the circular base of the cutting blade and the outer circumferential part of the flange are formed to be laterally symmetrical to a grindstone arranged at the cutting blade. Cutting water supplied from the outer circumferential side of the cutting blade by a cutting water supply means flows equally at both the sides of the cutting blade.