Basic constructions of the Delphi language and basic principles of structural programming are considered. Much attention is paid to algorithms for working with arrays, strings, structures, text and typed files. Various aspects of the use of procedures and functions, including recursive ones, are described in detail. Designed for students studying in the undergraduate program in the direction of 02.03.01. "Mathematics. Computer science." It can be used in schools with in-depth study of computer science.