With the appearance of new cracks in Leonardo's Last Supper at S. Maria delle Grazie, Milan, the many problems of the support of the fresco became pressing. Describes the first solution, a metal grid support, and the techniques for its placement; then discusses the planned examinations of the wall and its foundations, of the effect of vibrations, of temperature and humidity as well as of the material itself. With the results of these tests, eventual solutions will be proposed.