An endoscope apparatus includes illuminating section that performs illumination by an illuminating light of a first band, and performs illumination by an illuminating light of a second band for a first number of times that is two times or more, within a predetermined time period, image pickup section that picks up an image of an object illuminated by the illuminating section, and outputs a first picked-up image based on the illumination of the illuminating light of the first band, and a second picked-up image based on the illumination of the illuminating light of the second band, brightness calculating section that calculates a first brightness by color conversion matrix processing using a first image pickup signal based on the illumination by the illuminating light of the first band and a second image pickup signal based on illumination by first predetermined times out of the first number of times, and calculates a second brightness by color conversion matrix processing using the first image pickup signal based on the illumination by the illuminating light of the first band and a second image pickup signal based on illumination by times other than the first predetermined times out of the first number of times, and synthesizing section that multiplies the first and the second image pickup signals which become a source of the second brightness by a coefficient based on a ratio of a difference value of the first brightness and a target brightness, and the second brightness, and thereafter, synthesizes the result with the first and the second image pickup signals which become a source of the first brightness.
