In the 19th century infectious diseases such as tuberculosis, cholera, diphtheria or wound infections were the main cause of death worldwide. The doctor Robert Koch (1843-1910) discovered that these diseases were caused by bacteria. Together with his companions in Berlin, he identified infectious agents and routes of infection, thus paving the way for therapies and preventive measures. In 1891, Koch became director of the newly founded Royal Prussian Institute for Infectious Diseases, now the Robert Koch Institute (RKI). In 1905 he received the Nobel Prize for Medicine in recognition of the discovery of tuberculosis bacilli. Together with Louis Pasteur, Robert Koch is considered a pioneer of microbiology. There has been an exhibition at the RKI since 1910. It was set up after Koch's death, presented only pieces from the scientific legacy of the founder of the institute and was little changed for decades. In 2017, the museum was redesigned and expanded in cooperation with the Berlin Museum of Natural History: The historical exhibits are displayed on 180 square meters and at the same time the current working context is addressed. You can learn how the scientific image of health and illness has changed and how important Koch's and his students' ideas still are. The mausoleum of Robert Koch is also open to museum visitors.