To provide a capsule type endoscope properly observing the region of a subject by preventing the reflection of a light source image when the region in a subject provided through the boundary surface of a liquid and gas is photographed.

An illumination part 42 has a diffusion plate 422 for diffusing illumination light from an LED 421 in the emitting direction of the illumination light from the LED 421. Accordingly, the illumination light from the LED 421 is diffused by the diffusion plate 422 to illuminate an imaging visual field and, when the region in the subject provided through the boundary surface of the liquid and the gas is photographed, the light source image is reflected at the part of the boundary surface as it is to prevent the region in the subject from being reflected in an imaging part 41 and the region of the subject can be properly observed.