A capsule endoscope is disclosed that includes means for illuminating an object, means for imaging the object, and a transparent cover having a center of curvature. The transparent cover covers the illumination means and the imaging means, and the imaging means includes an objective optical system and an image detecting element. The illumination means is positioned relative to the image detecting element, as viewed axially from the object side of the capsule endoscope, so that an area that is symmetrically positioned about the optical axis of the objective optical system from a light emitting area of the illumination means overlaps an area of the image detecting element, but does not overlap any areas of the image detecting element that are used for image detection.