An image capturing device includes: an image capturing system having an optical axis; and at least one illumination system disposed at a position so as to surround the optical axis. The illumination system includes: a reflective surface deflecting part of illumination light; a refractive surface deflecting the other part of the illumination light and the illumination light reflected by the reflective surface; and an emission surface from which the illumination light refracted by the refractive surface is emitted. In a cross section including the optical axis, the reflective surface has an area inclined in such a direction as to become farther away from the optical axis, the refractive surface has an area inclined in such a direction as to approach the optical axis and is disposed between the reflective and emission surfaces. The emission end is disposed at a radial position between rear ends of the refractive and reflective surfaces.