It is possible to surely switch on/off the respective functions of a body-insertable apparatus, and maintain the on-state or the off-state securely. Provided is a magnetic filed generator that includes a magnetic sensor (3) with directivity that detects a magnetic field; an observation member that illuminates inside of a subject (1) to take images and thus to observe the inside; a switch control unit that controls on/off of the observation member when the magnetic sensor (3) detects the magnetic field; a capsule endoscope (2) that includes a sending member for sending information including observation images to outside of the subject 1; a magnetic filed generating unit (4) that emits a temporary magnetic field toward inside of the subject (1); an arm drive unit (5) that changes the direction of the emitted magnetic field; and a control unit (C) that controls illuminating of the magnetic field by the magnetic and driving of the arm drive unit (5).
