With a tutorial approach, this book covers the most impor- tant aspects of the scattering of electromagnetic radiation from structures (isolated or on a substrate) whose size is comparable to the incident wavelength. Special emphasis is placed on the electromagnetic problem of microstructures lo- cated close to an interface by reviewing the most important numerical methods for calculating the scattered field. The polarization propagation and the statistics of scattered in- tensity in microstructured targets are also presented from a didactic point of view. The final part of the book is dedi- cated to the most significant applications in both basic and applied research: surface enhanced Raman scattering, monito- ring and detection of surface contamination by particles, optical communications, particle sizing and others.