A coefficient calculator calculates a correlation coefficient representing a correlation between a normal frame, which is imaged in a state in which normal light is applied to a subject, and a special frame, which is imaged in a state in which special light is applied to the subject; and a processing unit that applies image processing to the special frame so that a part in which the correlation coefficient is high and a part in which the correlation coefficient is low are displayed differently in the special frame. Further provided are: a first determination unit that calculates, for each pixel or each area of the normal frame, a first determination value representing a probability that a predetermined site is imaged; and a second determination unit that calculates, for each pixel or each area of the special frame, a second determination value representing a probability that a predetermined site is imaged.