MC X-Ray is a new Monte Carlo program that is an extension of the Monte Carlo programs Casino and Win X-Ray since it computes the complete x-ray spectra from the simulation of electron scattering in solids of various types of geometries. MC X-Ray allows up to 256 different regions in the materials having shape of spheres, cylinders and combinations of horizontal and vertical planes. All these regions can have a different composition. This program was written by Pierre Michaud under the supervision of Pr. Gauvin. Dr. Hendrix Demers improved and validated the x-ray spectrum computation of MC X-Ray.