A chip manufacturing method for dividing a workpiece along a projected dicing line established thereon into a plurality of chips includes a modified layer forming step of applying a laser beam that is transmittable through the workpiece and focused into a first focused point and a second focused point, to the workpiece along the projected dicing line while positioning the first focused point and the second focused point within the workpiece, thereby forming a plurality of modified regions in the workpiece. The modified layer forming step includes applying the laser beam to the workpiece while forming one of the modified regions around a region where the first focused spot is positioned, and positioning the second focused spot in superposed relation to another modified region that has already been formed in the workpiece.

A chip manufacturing method for dividing a workpiece along a projected dicing line established thereon into a plurality of chips includes a modified layer forming step of applying a laser beam that is transmittable through the workpiece and focused into a first focused point and a second focused point, to the workpiece along the projected dicing line while positioning the first focused point and the second focused point within the workpiece, thereby forming a plurality of modified regions in the workpiece. The modified layer forming step includes applying the laser beam to the workpiece while forming one of the modified regions around a region where the first focused spot is positioned, and positioning the second focused spot in superposed relation to another modified region that has already been formed in the workpiece.