A bronchial image generation unit generates a bronchial image and a position information acquisition unit acquires position information of an endoscope in a bronchus. A passage position information acquisition unit acquires passage position information representing a passage position of the endoscope and a passage propriety information acquisition unit acquires passage propriety information representing portions through which the endoscope can be passed and a portion through which the endoscope cannot be passed. A display control unit displays a bronchial image by changing a display state of a portion of the bronchial image through which the endoscope has been passed and a portion of the bronchial image through which the endoscope has not been passed using the passage position information, and changing a display state of portions of the bronchial image through which the endoscope can be passed and cannot be passed using the passage propriety information.
