The Human Detector alarm box is a small and compact unit that can be mounted under a pedestal or behind an exhibtion wall, for example. Any number of Human Detector alarm modules can be connected to the alarm box via cable. The necessary operating voltage is also supplied by the alarm box from a central location. The alarm box has a freely programmable voice module. The Human Detector alarm box can of course be activated or deactivated. This is useful when carrying out cleaning work. An additional Human Detector alarm module (HD-SM) built into the alarm box forwards the alarm to a higher-level control centre via radio. Among other things, this is necessary for controlling video cameras, for alarm logging or for connecting to intruder detection systems.