The microwave imaging is generally perceived as the reconstruction of permittivity distribution function of the medium-under-test from the measurement of the scattered electromagnetic fields interacting with the medium. It has got application in the field of industrial and biomedical tomography, where different components or tissues may be differentiated due to their substantial difference in dielectric properties. One of the most crucial parts of the microwave imaging process is the development of an efficient inversion algorithm for reconstructing the depth-dependent permittivity profiles of dielectric objects from the measurement of scattering coefficients. This book mainly deals with this kind of problem, and accordingly introduces a quite general approach for finding a stable solution of the corresponding electromagnetic inverse scattering problem. An innovative experimental setup is also described here for the free-space microwave imaging of dielectric bodies. The book is intended for Scientist and Engineers from industry and research institutions, as well as for graduate students desirous of working in the field of electromagnetic inverse scattering and microwave imaging.