PROBLEM TO BE SOLVED: To equalize the contrast of blood vessels in an observation image even in an endoscope including a light guide with different light transmission characteristics.SOLUTION: A processor device includes an image processing part for processing respective image signals output from a plurality of endoscopes including light guides with different light transmission characteristics. In a blood vessel emphasizing observation mode, the image processing part changes contents of image processing according to a model of an endoscope. The image processing part executes a contrast emphasizing process for an image signal output from an endoscope whose light transmission rate for the light for vascular information observation is relatively low, in addition to the image process for an image signal output from an endoscope whose light transmission rate is high.
