A new translational couch unit with extended potentials of dose optimization by variable velocity and a comfortable user interface with integrated patient administration was developed at the university clinic of Regensburg. Materials and Methods: The concept and construction were elaborated in legal accordance with the in-house manufacture conditions mentioned in the German Medical Devices Act. In particular we have implemented a concept of functional safety based on a controller unit, an independent monitoring unit and self-testing procedures. Redundant safety relevant hard- and software components are continuously checked against each other. In case of any malfunction the translation movement and the linear accelerator are stopped. Gap-free continuation of the treatment will be possible after elimination of the cause of the interrupt. Results and Conclusion: After the testing of the implemented functional safety features including the risk assessment and management, electrical safety, electromagnetic compatibility by accredited technical experts the translational couch system complies with the requirements of the Medical Devices Act and can be operated in terms of in-house application. The presented certification procedure can motivate other radiation departments to develop own systems for in-house usage.