DRIVING ASSISTANCE DEVICE

A driving assistance device includes an object detection unit, an acquisition unit acquiring a first value of a relative speed of an approaching object with respect to an own vehicle, a ghost determination unit, and an assistance determination unit. The ghost determination unit calculates a second value of the relative speed of the approaching object in accordance with a speed of the own vehicle and a value of the relative speed of a following object located between the own vehicle and the approaching object; calculates, as a speed difference, an absolute difference between the first value of the relative speed and the second value of the relative speed; calculates, as an azimuth difference, an absolute difference between an azimuth of the following object and an azimuth of the approaching object; and determines whether the approaching object is the ghost target based on the speed difference and the azimuth difference.