Teaching university courses, which deal with the phenomena of theelectromagnetic (EM) substantiality and their applications, is ratherdifficult due to their abstract nature. Therefore, teaching has to beaccompanied by clear explanations and by simulations illustrating theexamined topics. This is why an electronic textbook (ET) of EM wavesand applications was developed. The ET presents theoreticaldescriptions of selected EM phenomena on two levels - on a bachelor'sone and a master's one. Descriptive parts of the ET are completed bycomputer programs, which enable the reader to simulate the studiedphenomena. Moreover, the ET explains the practical implementation ofsimulation routines in MATLAB, which helps students to understand arelationship between rather complicated mathematics and a relativelysimple source code of its software implementation. Since the ET isfreely accessible on the web, students can use it whenever as aclassical textbook, a handbook or a software package. This factpositively influences the students' knowledge and understanding asproven by our experience.