DRIVING ASSISTANCE DEVICE

A memory stores an assistance pattern including a first periphery sensor map indicating a map in a periphery of a vehicle and an assistance content of driving assistance of the vehicle corresponding to the first periphery sensor map. A processor (sensor information acquisition unit ) acquires sensor information indicating information on an object in the periphery of the vehicle sensed by a sensor. A processor (periphery sensor map acquisition unit ) acquires a second periphery sensor map based on the sensor information. A processor (map similarity search unit , and assistance instruction unit ) performs driving assistance of the assistance content corresponding to the first periphery sensor map when the second periphery sensor map is similar to the first periphery sensor map.