A digital camera 1 includes an image composition unit 52 and a composite position determining unit 53. The image composition unit 52 acquires a plurality of images which have been captured continuously. The composite position determining unit 53 sets candidate areas for determining composite positions in adjacent images, from the plurality of images acquired by the composite position determining unit 52. Furthermore, the composite position determining unit 53 determines composite positions of the adjacent images based on a degree of similarity between the set candidate areas. The image composition unit 52 combines the adjacent images at the determined composite positions.