The building block of today's digital world is based on the silicon technology. Moreover, Si is widely available, well studied and therefore will remain a very important part of digital technologies. In recent years the synthesis of semiconductor materials, structures and devices with dimensions ranging from a few angstroms to several nanometers, by a number of techniques brings a new quality in the miniaturization of such semiconductor structures. The Si nanostructures show different mechanical, electrical and optical properties compared to the bulk Si. An interesting aspect of confinement is that through varying of the size of the materials, their physical properties can be tuned. The possible future application of silicon nanowires (SiNWs) is conditional upon the studying of its mechanical, electrical and optical properties. In this work the elastic properties, such as the bulk modulus and isothermal compressibility and the thermal properties of SiNWs were studied by means of Raman spectroscopy, accompanied by transmission electron microscopy.