A tracking device comprising: an image input unit adapted to receive an image for each time that the image is obtained by imaging using an imaging unit, resulting in a plurality of images; a first moving body detection unit adapted to calculate an optical flow using the plurality of images input to the image input unit and to detect a position and a direction of movement of a moving body based on the calculated optical flow; a second moving body detection unit adapted to detect a position and a direction of movement of the moving body based on a difference between a plurality of overhead images generated based on the plurality of images; a third moving body detection unit adapted to detect a position and a direction of movement of the moving body by using detection results from the first moving body detection unit and the second moving body detection unit; a tracked moving body confirmation unit adapted to determine a moving body to be tracked based on detection results from the first to third moving body detection units (51, 52, 53); an estimation unit adapted to estimate a future position and direction of movement of the tracked moving body determined by the tracked moving body confirmation unit; and a tracking unit adapted to track the tracked moving body and to identify a position of the tracked moving body using any one of the respective positions of the moving body detected by the first to third moving body detection units (51, 52, 53) and the estimated position estimated by the estimation unit, characterised in that the tracked moving body confirmation unit is adapted to store a moving body certainty factor corresponding to an index indicating a probability of determining a moving body candidate corresponding to a candidate for the tracked moving body as a tracking target, to estimate a future position of the moving body candidate, and to increase or decrease the moving body certainty factor based on a relationship between the future position of the moving body candidate estimated by the tracked moving body confirmation unit, and the position of the moving body detected by the third moving body detection unit, the position of the moving body detected by the first moving body detection unit, and the position of the moving body detected by the second moving body detection unit to determine the moving body candidate as a new tracked moving body when the moving body certainty factor is greater than or equal to a predetermined value. an image input unit adapted to receive an image for each time that the image is obtained by imaging using an imaging unit, resulting in a plurality of images; a first moving body detection unit adapted to calculate an optical flow using the plurality of images input to the image input unit and to detect a position and a direction of movement of a moving body based on the calculated optical flow; a second moving body detection unit adapted to detect a position and a direction of movement of the moving body based on a difference between a plurality of overhead images generated based on the plurality of images; a third moving body detection unit adapted to detect a position and a direction of movement of the moving body by using detection results from the first moving body detection unit and the second moving body detection unit; a tracked moving body confirmation unit adapted to determine a moving body to be tracked based on detection results from the first to third moving body detection units (51, 52, 53); an estimation unit adapted to estimate a future position and direction of movement of the tracked moving body determined by the tracked moving body confirmation unit; and a tracking unit adapted to track the tracked moving body and to identify a position of the tracked moving body using any one of the respective positions of the moving body detected by the first to third moving body detection units (51, 52, 53) and the estimated position estimated by the estimation unit, characterised in that the tracked moving body confirmation unit is adapted to store a moving body certainty factor corresponding to an index indicating a probability of determining a moving body candidate corresponding to a candidate for the tracked moving body as a tracking target, to estimate a future position of the moving body candidate, and to increase or decrease the moving body certainty factor based on a relationship between the future position of the moving body candidate estimated by the tracked moving body confirmation unit, and the position of the moving body detected by the third moving body detection unit, the position of the moving body detected by the first moving body detection unit, and the position of the moving body detected by the second moving body detection unit to determine the moving body candidate as a new tracked moving body when the moving body certainty factor is greater than or equal to a predetermined value.