AUTONOMOUS DRIVING DEVICE, AUTONOMOUS DRIVING METHOD, AND PLURALITY OF NON-TRANSITORY STORAGE MEDIA

An autonomous driving device (21) to be mounted on a vehicle (20) includes a first ECU (211) configured to autonomously drive the vehicle (20), and a second ECU (212) configured to operate the vehicle (20) under remote control from an outside. The first ECU (211) is configured to keep an activated state while the second ECU (212) is operating the vehicle (20). The second ECU (212) is configured to keep a power saving state while the first ECU (211) is autonomously driving the vehicle (20).