The hold-up floor alarm bar is installed as a hold-up detector, in particular under counters, office desks, shop counters or similar installations. When the alarm bar is triggered, one of the two microcontacts is activated and the detector group is interrupted and an alarm triggered. Triggering is displayed permanently via two mechanical individual displays. This display can only be reset manually by piercing the relevant indicator and renewing after resetting. In this manner, it is possible to exactly identify the detector that has triggered the alarm. With each rail there are additional ten indicators delivered for replacing the pierced ones.