"Functional Analysis", written in a clear and entertaining style for senior and postgraduate students discusses Hilbert spaces, Banach algebras, Operator theory and Topological vector spaces. The book covers many standard results including the Hahn-Banach, open mapping and closed graph theorems; the Banach-Steinhaus and the Banach-Alaoglu theorems; Riesz-Fischer and Riesz representation theorems; Gelfand-Mazur and Gelfand-Neumark theorems; Bipolar theorem; and the Kolmogoroff criterion for normability. The book is designed for senior undergraduate and postgraduate students of mathematics and mathematical physics.