To provide an image processing device for visually clearly displaying a substantially degenerating spot (e.g., a floating or peeling spot) in a photographed target.

An image processing device includes: temperature difference setting-means 107 and 108 for setting a temperature difference; means for acquiring a zone that is included in an image photographed by an infrared digital camera and in which a temperature difference between a temperature of a pixel existing inside the zone and that of a pixel existing outside the zone and nearby the zone exceeds the above set temperature difference; and color information adding-means for adding, to a pixel existing inside the zone, color information different from color information of a pixel existing outside the zone and nearby the zone.