NOVELTY - The system (14) has a registration tool (17) which is provided with operator ID acquisition unit (29) that is configured to acquire operator ID from key registration operator. An information center (25) is provided with operator ID verification unit (32) that is configured to verify operator ID received from registration tool. A permission information notification unit (33) is provided to send registration permission signal (Sok) to registration tool through network to permit registration tool to perform registration process, when operator ID is verified.    USE - Electronic key registration system for vehicle such as hybrid vehicle, plug-in hybrid vehicle, electric vehicle and fuel cell vehicle.    ADVANTAGE - The registration tool can transmit the input serviceman ID to the information center through network communication, when registering the electronic key to the vehicle. The information center can transmit the registration permission signal to the registration tool through the network and permit key registration with the registration tool, when the serviceman ID is verified. The wrongful electronic key registration with the registration tool can be reduced or obviated, so that the security of the electronic key registration system can be improved. The serviceman ID assigned to one individual cannot be used or can be difficult to use by another individual, when serviceman ID is assigned to each serviceman. The information center can verify the serviceman ID, the time and location during where key registration is performed. Thus the security can be improved during key registration.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for registering electronic key.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the electronic key registration system.    Electronic key registration system (14)    Registration tool (17)    Information center (25)    Operator ID acquisition unit (29)    Operator ID verification unit (32)    Permission information notification unit (33)    Registration permission signal (Sok)