1. A microscope comprising: dark field illumination and bright field illumination which illuminate a preparat where a sample mounted on a slide glass is covered with a cover glass and a mounting agent; an image capturing unit which acquires a dark field image by image-capturing the preparat illuminated by the dark field illumination and which acquires a bright field image by image-capturing the preparat illuminated by the bright field illumination; and a magnified portion image acquisition area determination unit which detects an edge of the cover glass in the preparat based on the dark field image and the bright field image acquired by the image capturing unit and determines an internal area of the detected edge of the cover glass as a magnified portion image acquisition area of the sample.