First illumination light having a first peak wavelength range and second illumination light having a second peak wavelength range different from the first peak wavelength range are automatically switched and emitted. Identification processing for allowing a first object to be observed and a second object to be observed to be identified in a composite display image is performed. The first object to be observed has a first absorption peak in the first peak wavelength range of the first illumination light and the second object to be observed has a second absorption peak in the second peak wavelength range of the second illumination light.
