Patent ID: 7388469

Claim:
An electronic key apparatus for a vehicle, comprising: a vehicle starting operation device which is rotationally operable after a preliminary operation has been performed to start the vehicle; a rotation arresting device which constrains a rotational operation of the vehicle starting operation device so as to inhibit the start of the vehicle; a preliminary operation detection device which detects the preliminary operation; an ID checking device which performs a first ID check and a second ID check; and a release command transmission device which transmits a command to the rotation arresting device to release the constraint of the rotational operation of the vehicle starting operation device based upon the ID checking results of the first and second ID checks performed by the ID checking device, wherein the ID checking device is configured so that the first ID check is performed between a portable unit and the ID checking device after a driver has gotten into the vehicle, wherein if the first ID cheek succeeds a success indication for the first ID check is memorized, wherein the ID checking device is configured so that the second ID cheek is performed between the rotation arresting device and the ID checking device when the success indication for the first ID check has been memorized, wherein if the second ID check succeeds a success indication for the second ID check is memorized, wherein the release command transmission device is confirmed to transmit the command to the rotation arresting device to release the constraint of rotational operation of the vehicle starting operation device when a confirmation is made that both the success indications of the first and second ID checks have been memorized, wherein the release command transmission device is configured to transmit the command in response to the detection of the preliminary operation by the preliminary operation detection device.