A fabricating method of a semiconductor element includes the following steps. First, a substrate is provided. A metal gate structure and source/drain electrodes are already formed on the substrate. An amorphization process is performed in the source/drain electrodes to form an amorphous portion. An interlayer dielectric layer is formed on surfaces of the source/drain electrodes and a through hole contact is formed within the interlayer dielectric layer. A silicidation process is performed with the through hole contact and the amorphous portion of the source/drain electrodes to form a metal silicide layer. The fabricating method is capable of finishing the formation of the metal silicide layer in the condition that diameters of the through hole contact is becoming smaller and smaller.