PARKING ASSISTANCE METHOD AND PARKING ASSISTANCE DEVICE

The parking assistance method using a parking assistance device includes: when parking of a subject vehicle is performed in a manual mode, detecting a parking execution state of the subject vehicle and determining, based on the parking execution state, whether or not the parking toward a target parking space is necessary again; and when a determination is made that the parking toward the target parking space is necessary again, outputting, to a user interface, guidance information for switching a parking mode of the subject vehicle from the manual mode to an automated mode.