The well-known author H. Pietschmann addresses this book to physics teachers at higher schools and to physics students following their foundational training. Quantum mechanics eludes the intuitiveness we are familiar with from classical physics, but - and this is the core theme of the book - it can indeed be understood. H. Pietschmann succeeds in achieving this with simple means, providing teachers with a teaching aid and students with an introduction to the challenging university texts. The mathematical treatment does not play a central role; rather, the focus is on interpretation and thinking in quantum mechanical categories. Topics covered include the quantum hypothesis with a historical context, Schrödinger's theory, the interpretation of the wave function, and the measurement process.