This book, intended for graduate students studying applied math, analysis, and/or numerical analysis, provides the necessary tools to understand the structure and solvability of elliptic partial differential equations. "This book proposes a modern and practical approach to the classical subject of elliptic partial differential equations. It provides the correct functional framework for proving the existence of weak solutions in a broad selection of model problems, in anticipation of their numerical approximation (with finite element and boundary element methods). Assuming little beyond basic undergraduate mathematics, the book covers, step by step, an amount of topics that goes beyond most textbooks at this level. The first part (Chapters 1-9) is a self-contained and meticulously written text on linear elliptic boundary-value problems for graduate students. The remaining chapters tread in less explored territories with topics that cannot be found in many other textbooks. They include, for example, the study of Maxwell's equations with a detailed characterisation of the tangential trace spaces on Lipschitz domains, the Stokes-Darcy problem, dependence with respect to coefficients and elliptic problems on manifolds. Each chapter ends with final comments written in an attractive and personal style with judicious references to specialised literature. In addition, there is a good selection of problems that offers students the opportunity to further expand their knowledge. The richness of material, the clear exposition and distilled writing will appeal to students with interest in partial differential equations and their numerical analysis as well as to professional mathematicians. Even experienced instructors may benefit from the thoughtful approach of the book and from its original insight on the subject." -Salim Meddahi, Universidad de Oviedo