||This course is an introduction to formal quantum mechanics. It is to provide illustrations of quantum mechanics by taking many examples from different fields such as atomic physics, molecular physics and solid state physics. In these examples we concentrate on the quantum mechanical aspect of phenomena, often neglecting specific details. Whenever possible, the quantum mechanical results are compared with the classical ones in order to help the students develop his intuition concerning quantum mechanical effects. The intent, however is to treat in the course not only the basic formalism and related phenomena, but to take the student a step further to a consideration of generic and important application.