This review discusses Gerard Lallement's book "Semigroups and Combinatorial Applications," published in 1979. The book aims to present parts of semigroup theory related to automata theory, algebraic linguistics, and combinatorics. It is structured into three main parts: pure semigroup theory, free semigroups, codes, and languages, and combinatorial questions related to Burnside's problem and MacMahon's Master Theorem. The book provides a comprehensive treatment of semigroups, including their structure, Green's relations, and the prime decomposition theorem. It also covers language theory, focusing on regular languages and their connection to automata. The book is well-written, with clear explanations and numerous examples. While the treatment of language theory is somewhat biased towards semigroups, it offers an integrated account of these topics. The book is recommended for those with some knowledge of semigroups and language theory, as it provides a valuable resource for understanding the connections between these areas. The book is also noted for its clarity and usefulness, despite some minor errors and omissions. The review concludes that the book is a significant contribution to the field of semigroup theory and language theory.This review discusses Gerard Lallement's book "Semigroups and Combinatorial Applications," published in 1979. The book aims to present parts of semigroup theory related to automata theory, algebraic linguistics, and combinatorics. It is structured into three main parts: pure semigroup theory, free semigroups, codes, and languages, and combinatorial questions related to Burnside's problem and MacMahon's Master Theorem. The book provides a comprehensive treatment of semigroups, including their structure, Green's relations, and the prime decomposition theorem. It also covers language theory, focusing on regular languages and their connection to automata. The book is well-written, with clear explanations and numerous examples. While the treatment of language theory is somewhat biased towards semigroups, it offers an integrated account of these topics. The book is recommended for those with some knowledge of semigroups and language theory, as it provides a valuable resource for understanding the connections between these areas. The book is also noted for its clarity and usefulness, despite some minor errors and omissions. The review concludes that the book is a significant contribution to the field of semigroup theory and language theory.