Like many other German companies, between 1935 and 1945 NORIS was forced by the Nazi regime to release workers for military service and train foreign works or employ prisoners of war. During the air raids in 1944 parts of the production were relocated to Wunsiedel in the rural region near Nuremberg or to a bunker in the neighbouring town of Fürth to prevent the production equipment being destroyed and avoid production losses. On the 15th of April 1945 the factory finally had to close. During the subsequent fighting in Nuremberg 75% of the factory building was destroyed.
Immediately after the end of the war in May 1945, Ernst Schmidmer promptly applied to the Nuremberg Chamber of Commerce and Industry for the permit required to restart production. The clean-up work in the destroyed building complexes commenced in the same month. First of all, the ground floor of the factory building was repaired. By September 1945 the reconstruction had progressed to the extent that it was possible to return the production equipment to Nuremberg that had been relocated to Wunsiedel and Fürth. Finally, in April 1946 authorisation was given to restart production by the State Office for Precision Engineering and Optics.