Preface. The Laplacian. The Basic Examples. Curvature. Isoperimetric Inequalities. Eigenvalues and Kinematic Measure. The Heat Kernel for Compact Manifolds. The Dirichlet Heat Kernel for Regular Domains. The Heat Kernel for Noncompact Manifolds. Topological Perturbations with Negligible Effect. Surfaces of Constant Negative Curvature. The Selberg Trace Formula. Miscellanea. Laplacian on Forms. Bibliography. Index.