In a capsule endoscope (10), light emitting bodies (12a) in an illuminating unit (12) are disposed so that they are tilted outward from a central axis C of the capsule endoscope (10) and are tilted from a front side towards a back side, so that an optical axis of light L emitted from the light emitting bodies (12a) is shifted outward, and a brightness of illuminating light in an illuminating range of an observation central portion where light from a plurality of illuminating units (12) gather is substantially the same as a brightness of illuminating light in a surrounding portion excluding the central portion.
