1. A drive assist device comprising: a display unit that displays an image around a vehicle imaged by an imaging device installed on the vehicle; a setting unit that sets a target designated by a user on the image as a recognition target; a detection unit that detects a state change of the recognition target on the image when the recognition target is set; and a notification control unit that controls a notification device to notify the user of the detection result when the state change of the recognition target is detected.