GROOVE PROCESSING METHOD AND GROOVE PROCESSING DEVICE OF SUBSTRATE

PROBLEM TO BE SOLVED: To process a groove precisely by stabilizing a groove processing tool in forming a groove on a substrate by using a head on which the groove processing tool is supported so as to freely swing.SOLUTION: This groove processing method includes a substrate mounting step, a processing position operating step, and a processing step. In the substrate mounting step, a substrate is mounted on a table so that a line to be processed on the substrate is inclined within a predetermined angle range with respect to a Y direction. In the processing position operating step, a processing start position and processing end position of the line to be processed on the substrate are calculated. In the processing step, groove processing is carried out along the line to be processed while relatively moving a groove processing tool in an X direction and the Y direction with respect to the substrate based on the calculated processing start position and processing end position.