Parking assist device and method for assisting parking

According to a parking assist device and a method for assisting parking of the invention, when a parking assist is canceled after a start of the parking assist, and the parking assist is restarted, a target parking position (P2B) is reset at a reset position (P1B). In the invention, at this time, the target parking position (P2B) is determined based on a target parking position (P2A) which is set at a parking preparation position (P1A), and the determined target parking position (P2B) is displayed on a screen of a monitor (4) as a default display position of a target parking frame (11) at a reset time.