The present invention relates to an on-vehicle emergency notification device for performing a notification to an external emergency call center, in the event of an emergency. The on-vehicle emergency notification device is configured to allow a vehicle body number (VIN) and an emergency notification phone number (CIM number) to be registered therein in the form of a set, so as to enable the notification to the emergency call center, wherein the on-vehicle emergency notification device is configured such that: during execution of a factory mode for performing the registration of the vehicle body number and the emergency notification phone number, rewriting of the vehicle body number is permitted; and, after the registration of the vehicle body number and the emergency notification phone number is completed and then the factory mode is shifted to a market mode, the rewriting of the vehicle body number is prohibited.