A capsule endoscope is provided with an imaging lens, capsule body, and a transparent cover. The capsule body is formed hollow, and has an opening at an end. The imaging lens is provided such that a part thereof is positioned inside the capsule body and the rest is protruded from the opening. The transparent cover is formed into a dope shape, and is attached to the end of the capsule body to cover the imaging lens protruded from the opening. The inside of a patient's body is captured using the transparent cover and the imaging lens designed to satisfy the following condition: |fD|/fL≦70 where fD is a focal length of the transparent cover, and fL is a focal length of the imaging lens.