A capsule endoscope apparatus includes an illuminating device, an image pick-up device which picks up an image of an illuminated portion, and a radio transmitting device. The illuminating device in the capsule endoscope apparatus has a switching device which switches two or more light-emitting amount or light-emitting time. The radio transmitting device in the capsule endoscope apparatus transmits by radio waves image data obtained by the image pick-up device upon sequentially switching the two or more light-emitting amount or light-emitting time.