A self-running robot tracking and imaging a human body with an inexpensive arrangement includes: first to fourth sensors; a camera; a driving device moving the first to fourth sensors and camera simultaneously; a rotary encoder detecting that the first to fourth sensors and camera have stopped; a control unit which, upon detection of a heat source by one of the first to fourth sensors, controls the driving device such that the camera turns to the direction which the sensor detecting the heat source faced, and controls the camera so as to image an object after the camera has stopped, and controls the driving device such that the first to fourth sensors remain stationary for 3 seconds after the camera has stopped irrespective of whether a heat source is detected.