PROBLEM TO BE SOLVED: To provide a spot classification method for classifying a spot with high accuracy.SOLUTION: A color space conversion image wherein a color space of an image obtained by photographing the skin of a subject is converted is generated, a spot included in the color space conversion image is detected, a form characteristic amount and a color characteristic amount are calculated about the detected spot, and the spot is classified by a machine learning method based on the calculated form characteristic amount and color characteristic amount.