Abstract: A lock-picking prevention apparatus is adaptable to a lock (120) having a lock hole (121) and an abutment driver pin (122) for restricting and releasing a key. The apparatus includes a locking body (102) having a front end abutment hook (102d) abutted by the abutment driver pin (122) when the lock-picking prevention apparatus is inserted into the lock hole (121) so as to bury its internal space, an operating bar (102) provided so as to slide over the abutment driver pin (122) to provide guidance, and a new key (110). At the time of unlocking using the new key (110), the operating bar (103) pushes in the abutment driver pin (122) to release the abutment of the front end abutment hook (102d) so as to enable the locking body (102) to be pulled out. The lock-picking prevention apparatus brings about a situation which is equivalent to a plurality of locks being provided.