A capsule endoscope 10 includes, inside a capsule casing, an information acquiring section 26 that acquires information on an inside of a body of a subject, a battery 19 that supplies power, a detection section 20 that, upon detection of introduction to the inside of the body of the subject, outputs a detection signal S20, a signal receiving section 11 that receives a control signal from an outside and outputs an internal signal S1, and a control section 21 that controls power supply from the battery 19 to the information acquiring section 26 according to the internal signal S1 and the detection signal S20.
