Provided are: a device for sensing a cyber-attack on a vehicle and carrying out notification of such attack, the device enabling notification by a suitable notification method which is in accordance with the state of the driver; and a method. A cyber-attack notification device (10) is installed on a vehicle and carries out notification with respect to a cyber-attack on the vehicle. The cyber-attack notification device comprises: a cyber-attack sensing unit (330) for sensing a cyber-attack on the vehicle; a driver state input unit (310a) for acquiring information indicating the state of the driver; a notification method determination unit (360) for determining an apparatus that is to be notified, from between a first apparatus (520) that is inside the vehicle and a second apparatus (510) that is outside of the vehicle; and an abnormality notification unit (380) for notifying the determined apparatus of information related to the cyber-attack. The notification method determination unit determines the apparatus to be notified of the information, on the basis of whether the driver is inside the vehicle or outside of the vehicle.