A capsule endoscope is provided with lighting means for illuminating the interior of a living body, an image pickup means for capturing an image of a site illuminated by the lighting means, and a transparent cover which houses the image pickup means and the lighting means within a sealed, cylindrical-shaped capsule case. The image pickup means includes an objective optical system having a depth of field. An object within the depth of field of the objective optical system is illuminated more evenly than possible with a single lighting means by arranging multiple lighting means at the periphery of the objective optical system and causing the beams from individual lighting means to overlap in specified ways so that a nearly uniform illumination of an object of interest is achieved. Light diffusers may be employed to diffuse the light from the light sources, and a color correction filter may be used.