To provide a locking device excellent in security without placing an economical or operational burden on users.
The locking device includes: a mechanical operating part 15 which is provided on a subject to be locked, such as a door 1, and locks and unlocks the subject in such a way that it operates for locking and unlocking in response to a mechanical operation body made with a portable operating element such as a key K or a fitted operating element such as a thumbturn; and an electronic operating part 16 which locks and unlocks the subject independently of the mechanical operating part 15 in such a way that it unlocks the subject in response to a predetermined unlock signal related to the recognition of an image of the portable operating element that is the same as or different from the above-mentioned portable operating element. The mechanical operating part of a cylinder lock is preferably utilized.
TSUGAWA AKIHIKO
NISHIJIMA SHUICHI
