Parking Assistance Method and Parking Assistance Device

A parking assistance device configured to assist parking of an own vehicle at a target parking position, the parking assistance device comprising:

• a sensor configured to detect a surrounding environment of the own vehicle;
• a storage device;
• and
• a controller configured to extract a target object in surroundings of the target parking position from surrounding environment data acquired by detecting a surrounding environment of the own vehicle using the sensor and store the extracted target object in a storage device as a learned target object in conjunction with the target parking position, in advance, and assist, at a time of parking the own vehicle at the target parking position after storing the learned target object in the storage device, parking of the own vehicle at the target parking position, based on the learned target object,
• wherein the controller, when length of an advancing travel section, the advancing travel section being a section where the own vehicle travels in an advancing direction, within a data detection section, the data detection section being a section where the own vehicle travels and acquires the surrounding environment data, is greater than or equal to a predetermined threshold value, stores the extracted target object as a learned target object and, when length of the advancing travel section is not greater than or equal to a predetermined threshold value, does not store the extracted target object as the learned target object.