A prober for testing devices in a repeat structure on a substrate is provided with a probe holder plate, probe holders mounted on the plate, and a test probe associated with each holder. Each test probe is displaceable via a manipulator connected to a probe holder, and a substrate carrier fixedly supports the substrate. Testing of devices, which are situated in a repeat structure on a substrate, in sequence without a substrate movement and avoiding individual manipulation of the test probes in relation to the contact islands on the devices, is achieved in that the probe holders are fastened on a shared probe holder plate and the probe holder plate is moved in relation to the test substrate.