This invention relates to capturing an image of a subject as a three-dimensional image using a single image-capturing apparatus. The image-capturing apparatus includes a first polarization means, a lens system, and an image-capturing device array having a second polarization means. The first polarization means includes first and second regions arranged along a first direction, and the second polarization means includes multiple third and fourth regions arranged alternately along a second direction. First region transmission light having passed the first region passes the third region and reaches the image-capturing device, and second region transmission light having passed the second region passes the fourth region and reaches the image-capturing device. Thus, an image is captured to obtain a three-dimensional image in which a distance between a barycenter BC1 of the first region and a barycenter BC2 of the second region is a base line length of parallax between two eyes.