A moving object tracking device comprising: an acquirer configured to acquire a plurality of images; a tracker configured to generate a plurality of pieces of tracking information indicating information obtained by tracking one or more moving objects included in the images, wherein each of the plurality of pieces of tracking information indicates: for each image of a respective plurality of images, a position of a moving object of the one or more moving objects in the image and an imaged time of the image, where in the respective plurality of images are those images of plurality of images from which the moving object is detected and having a difference in imaged time equal to or smaller than a predetermined value; a first associator configured to generate first associated tracking information by collecting pieces of tracking information having a mutual time difference equal to or smaller than a threshold among the plurality of pieces of tracking information as pieces of tracking information corresponding to a same moving object of the one or more moving objects; a second associator configured to: extract authentication information, respectively, for the first associated tracking information and one or more pieces of the plurality of pieces of tracking information which have not been associated by the first associator; and generate second associated tracking information by associating the first associated tracking information and the one or more pieces of the plurality of pieces of tracking information having authentication information matching each other; and an output unit configured to output the second associated tracking information. an acquirer configured to acquire a plurality of images; a tracker configured to generate a plurality of pieces of tracking information indicating information obtained by tracking one or more moving objects included in the images, wherein each of the plurality of pieces of tracking information indicates: for each image of a respective plurality of images, a position of a moving object of the one or more moving objects in the image and an imaged time of the image, where in the respective plurality of images are those images of plurality of images from which the moving object is detected and having a difference in imaged time equal to or smaller than a predetermined value; a first associator configured to generate first associated tracking information by collecting pieces of tracking information having a mutual time difference equal to or smaller than a threshold among the plurality of pieces of tracking information as pieces of tracking information corresponding to a same moving object of the one or more moving objects; a second associator configured to: extract authentication information, respectively, for the first associated tracking information and one or more pieces of the plurality of pieces of tracking information which have not been associated by the first associator; and generate second associated tracking information by associating the first associated tracking information and the one or more pieces of the plurality of pieces of tracking information having authentication information matching each other; and extract authentication information, respectively, for the first associated tracking information and one or more pieces of the plurality of pieces of tracking information which have not been associated by the first associator; and generate second associated tracking information by associating the first associated tracking information and the one or more pieces of the plurality of pieces of tracking information having authentication information matching each other; and an output unit configured to output the second associated tracking information.