To provide equipment for preventing the fraudulent opening of an opening/closing body, which issues an alarm by detecting that the opening/closing body such as a window and a door is fraudulently opened, and which inhibits intrusion by devising the constitution of a key part and its periphery so that the operations of breaking a windowpane etc. and opening or destroying a lock can require a long period of time, and by employing such a constitution that the alarm is necessarily sounded on site when the unlocking and destruction operations are performed.

This equipment for preventing the fraudulent opening of the opening/closing body comprises: the opening/closing bodies 50 and 55 for opening/closing an opening 101 of a building; a locking means 60 which inhibits the opening of the opening/closing body by being transferred to a locking state when the opening/closing body is in a closing position to close the opening, and which allows the opening of the opening/closing body by being transferred to an unlocking state; an unlocking inhibiting means 2 for inhibiting an unlocking operation by covering at least a part of the locking means; and a detection means 20 for detecting that the unlocking inhibiting means is removed.