There is provided a acne-affected skin determination method including: setting an upper region and a lower region so as to vertically divide the face of a subject into two regions； acquiring a measurement value of the amount of moisture in the lower region； acquiring a measurement value of the amount of moisture in the upper region； calculating a target moisture value indicating the level of the amounts of moisture distributed in one of the upper region or the lower region and a reference moisture value indicating the level of the amounts of moisture distributed in a reference region including the other of the upper region and the lower region, based on the measurement values of the amounts of moisture in the upper region and the lower region； obtaining the degree of change in moisture of the target moisture value with respect to the reference moisture value； and determining the ease of generation of acne in the face of the subject based on the obtained degree of change in moisture.
