In an image-obtainment-apparatus that obtains an image of an observation-region by imaging, by an imaging-device, light output from the observation-region illuminated with illumination-light, when the light-amount of the illumination-light illuminated the observation-region is less than or equal to first-threshold-value, the electronic-shutter-speed is controlled at first-constant-speed, and the light-amount of the illumination-light is controlled based on the light-amount of the illumination-light illuminated the observation-region. When the light-amount of the illumination-light illuminated the observation-region is greater than first-threshold-value and less than or equal to second-threshold-value, the electronic-shutter-speed is controlled at a speed based on the light-amount of the illumination-light illuminated the observation-region, and the light-amount of the illumination-light is controlled at a predetermined constant light-amount. When the light-amount of the illumination-light illuminated the observation-region is greater than second-threshold-value, the electronic-shutter-speed is controlled at second-constant-speed, and the light-amount of the illumination-light is controlled based on the light-amount of the illumination-light illuminated the observation-region.