A driving assistance device 1 performs autonomous driving based on an output from a sensor unit 13 that acquires information on surroundings of a vehicle or information on the state of the vehicle. The driving assistance device 1 stores an autonomous driving determination table Tj based on autonomous driving compatibility information 24. By referring to the autonomous driving determination table Tj based on sensor information 23 on the sensor unit 13 and road element information Ie on a predetermined road section, the driving assistance device 1 determines a set of an autonomous driving function Fc and an automation level Lv that can be performed in the predetermined road section.