To acquire a composite image of an angle of view larger than that of the specification of a single photographic lens.

Imaging units 1 and 2 that can be inclined in order to adjust the photographing direction include photographic lenses 1a and 2a and imaging elements 1b and 2b having a rectangular imaging surface. Photographing is performed while the photographing ranges of the imaging units 1 and 2 are matched with each other, and one stereo image is composed from respective output images of the imaging elements 1b and 2b. Then, the imaging elements 1b and 2b are rotated by 90° by motors 1d and 2d for imaging element rotation, respectively, and the imaging units 1 and 2 are inclined outside (+y direction) so that the photographing ranges of the imaging units 1 and 2 partially overlap each other, and photographing is performed, thereby composing a high-definition image of a large angle of view from respective output images of the imaging elements 1b and 2b.