Tracking processing device and tracking processing method

[Problem] To accurately track an object to be tracked regardless of the surrounding environment. [Solution] A tracking processing device 3 is configured that is provided with a tracking processing unit 11 for carrying out processing for tracking an object to be tracked and a degree-of-congestion calculation unit 22 for calculating the degree of congestion of targets in an area that includes a predicted position of the object to be tracked. The tracking processing unit 11 carries out the processing for tracking the object to be tracked according to the value of the degree of congestion calculated by the degree-of-congestion calculation unit 22.