This book is intended as a textbook for a course on Functional Analysis; but it is also intended to be useful for scientists and engineers. Some of the welcome features of the book are : proofs and motivation for the theory and applications; keeping in view the importance of the subject Operator theory and Fixed point theory with applications are given more attention than most other books; Banach algebras with spectral analysis are treated in great detail; there is also a detailed treatment of sequence spaces, variational inequalities and complementarity problems; best approximation and computational methods in normal linear spaces are also included; exercises of various levels of difficulty are given at the end of every chapter; a few illustrative examples are also worked out.