In this paper I present a program Maxima, which is one of the best computer algebra system (CAS). The program is easy to use and offers many possibilities. In the text the interface, basic commands, and various examples to facilitate complex calculations in almost every field of mathematics are preented. I prove that the program can be used in secondary schools, upper secondary schools and college. Program’s capabilities are presented, including, among others, differentiation and symbolic integration, symbolic solving equations (including differential), simplifying algebraic expressions, matrix operations, the possibility of drawing graphs of 2D / 3D and others.