CUTTING BLADE DETECTING MECHANISM FOR CUTTING DEVICE

PROBLEM TO BE SOLVED: To provide a cutting blade detecting mechanism for a cutting device capable of surely detecting that a circular cutting edge forming a cutting blade is totally damaged by separating from an outer peripheral edge of a base.SOLUTION: The cutting blade detecting mechanism for a cutting device includes a light-emitting means arranged at one side of the cutting blade having the circular cutting edge for cutting a workpiece held on a chuck table, a light-receiving means arranged so as to face to the light-emitting means at the other side of a rotary direction of the cutting blade and receiving the light irradiated with the light-emitting means, and a control means for determining conditions of the circular cutting edge on the basis of the amount of light received with the light-receiving means. The cutting blade is composed of the circular base and the circular cutting edge mounted on a side face of an outer peripheral section of the circular base and formed so as to protrude from the outer peripheral edge of the circular base, and a light-emitting face of the light-emitting means and a light-receiving face of the light-receiving means are arranged at a location where a part of the light-emitting face and the light-receiving face is shielded with the outer peripheral section of the circular base.