A capsule endoscope includes a capsule body having a cylindrical section, and a transparent cover. In the capsule endoscope, a reflective optical system, an image forming optical system, LEDs, and an image sensor are contained. The cylindrical transparent cover is disposed in the middle of the cylindrical section in a longitudinal direction. Through the transparent cover, light is transmittable in 360 degrees around a central axis of the capsule body. The reflective optical system reflects the light that has entered the capsule body through the transparent cover to the image forming optical system. The image forming optical system forms a 360 degree image around the whole circumference of the cylindrical section on the image sensor. The 360 degree image is circular in shape.