The Montessori teaching method is a popular approach to support the development of young children, which is successfully implemented in many countries of the world. One of the important principles of the Montessori method is a prepared environment that meets the developmental needs of young children. This manual describes the learning environment and application methods aimed at enabling young children to actively interact with their environment, explore and discover its meaning by themselves, have their own thinking and responsibility when doing something, and support them to be able to do things independently. The "Montessori teaching" manual consists of three series of parts: life skills, senses, mathematics, language, science, and art. The first series was translated by B.Myagmar and D.Khajidmaa from the Teaching Methodology Department at the School of Preschool Education in 2023.