The present embodiments relate to a mammography unit may be improved, by provision of a positioning device for a mammography unit, comprising a device support section for accommodating the radiation source and an object support device for accommodating the object holder for the relative positioning of a radiation source and an object holder. The object support section may be and/or is connected to the mammography unit by means of a connector element, wherein the device support section is mounted such as to be able to rotate relative to the connector element.