A thermal image sensor including: a plurality of infrared detector elements that detect infrared light in a detection area; and rotors that scan the detection area in a scanning direction to detect, with the plurality of infrared detector elements, infrared light in an area to be captured as a single thermal image. The plurality of infrared detector elements include infrared detector elements arranged in mutually different positions in a rotational direction corresponding to the scanning direction of the plurality of infrared detector elements.