The tutorial consists of three parts: "Vector analysis (mathematical field theory)," "Edge problems. Orthogonal systems of functions," "Equations of mathematical physics." Many solved examples and problems. In the book: Bessel Functions. Hankel and Neumann functions. Legendre polynomials. Spherical functions. Hermite polynomials.? -Dirac function as a singular generalized function. Airy function. Maxwell equations. Expression of the Laplace operator in spherical and cylindrical coordinates. Solving the Dirichlet problem for a circle. Problems leading to the study of solutions of Laplace equations. Formulation of boundary value problems...