A focusing device includes a distance information acquisition section acquiring information on a distance to a subject based on a plurality of image data acquired by taking images of the subject at a plurality of different viewpoint positions. A subject detection section detects a first area and a second area based on the distance information and threshold information for the distance range within which a subject of interest that obstructs a main subject in the subject is present. In the first area, the subject of interest is present in each of the plurality of image data. In the second area, the subject of interest is not present. A focusing estimation section estimates the focusing of the main subject based on the distance information on the second area in each of the plurality of image data.