With a tutorial approach, this book covers the most important 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 located close to an interface by reviewing the most important numerical methods for calculating the scattered field. The polarization propagation and the statistics of scattered intensity in microstructured targets are also presented from a didactic point of view. The final part of the book is dedicated to the most significant applications in both basic and applied research: surface enhanced Raman scattering, monitoring and detection of surface contamination by particles, optical communications, particle sizing and others.