Abstract: The invention is related to an armor kit in a safe, the said kit consisting in armor plates (11, 12, 15, 18) that are juxtaposed to the inner walls of the safe of ATMs and similar equipment, where the attachment of the said plates to the said walls is provided by way of removable retention means, such as screws fitted in threaded holes previously present in the said walls. The kit further comprises means for rigid joining between plates, such means consisting in flat perforated metal plates (13) or in plates that are folded/bent to form angle pieces (16, 19), provided with through-holes for the accommodation of screws.