This course is about elliptic variational problems, stemming from boundary value problems for certain partial differential equations, and their systematic numerical approximation by the finite element method. Today this method is a very powerful tool for the simulation of complex physical processes in science and engineering. In this course we study the origin of elliptic boundary value problems, their transformation into elliptic variational problems, and the systematic numerical solution by the finite element method. The implementaiton of the method and the application to some typical model problems arising in science and engeneering will be discussed.