PROBLEM TO BE SOLVED: To surely capture fluorescence images of arteries with high contrast without increasing dosage of a fluorescence agent, and to reduce a data amount of the fluorescence images.SOLUTION: After an fluorescence agent is dosed, fluorescence images are captured at a first imaging interval, and then it is switched to a second imaging interval that is longer than the first imaging interval to capture fluorescence images. That is, when capturing the fluorescence images of arteries which start emission of fluorescence prior to veins and have a higher blood flow speed, the fluorescence images are captured at the first imaging interval that is relatively shorter. When capturing the fluorescence images of veins which emit fluorescence after the arteries and have a lower blood flow speed, the fluorescence images are captured at the second imaging interval that is relatively longer.
