The Laboratory of study of microstructures, mechanics and material sciences (French: Laboratoire d'étude des microstructures et de mécanique des matériaux), also known as the LEM3, is a French laboratory of research located in Metz.

It is under the authority of Arts et Métiers ParisTech,[1] University of Lorraine and ENIM.

The LEM3 plays an important role in the competitiveness organization "Materialia" and in the new research institute M2P.

In 2013, a microscope with the electron backscatter detector technology was funded by the Lorraine Region (one million euros).

The laboratory also has a high-strength multi-axial tensile test machine with a capacity of 72 tons per axis.