Debris determination method

A debris determination method of determining, using an image obtained by an appearance inspection device, debris that occurs around a hard laser mark on a backside of a wafer after the hard laser mark is formed on the backside or after the backside is polished after formation of the hard laser mark, comprising:

• a step A of calculating reference luminance from a grayscale image obtained by the appearance inspection device;
• a step B of extracting a hard laser mark-printed region including the hard laser mark from the grayscale image;
• a step C of excluding a dot portion of the hard laser mark from the extracted hard laser mark-printed region;
• a step D of extracting, with reference to the reference luminance, a region of the debris from the hard laser mark-printed region from which the dot portion of the hard laser mark has been excluded;
• and
• a step E of determining presence or absence of the debris in the hard laser mark-printed region based on the extracted region of the debris.