PURPOSE: To obtain a target tracking device which can continuously track the same target even when continuous tracking is obstructed.

CONSTITUTION: A tracking impossible state occurs due to the relation between the installed position of radar equipment and tracking position of a specific target. Whether or not the tracking impossible state occurs due the topography is discriminated by analyzing a contour map data memory 6, route data memory 9, etc. A tracking gate generator 1 generates tracking gate width data and estimated target tracking position from the latest target tracking position and one-scan delaying device 2 delays the data by one radar scanning time. A comparator 3 discriminates whether the position of the specific target is at the estimated tracking position by comparing the output of the delaying device 2 with the target position data in magnitude. An interpolating target generator 11 generates the interpolating target signal corresponding to the estimated target tracking position and, when the tracking impossible state occurs, a tracking target selector 4 interpolates the lacking data by selecting the interpolating signal so that the tracking can be executed continuously.