This book emphasizes the experimental aspects of the author's own laboratory. Instead of merely presenting a dry collection of knowledge, the author unfolds to the readers his vivid experiences of enthusiasm, sheer pleasure, and yet frustrations in the course of his own research. In this way, the book aims to arouse the reader's curiosity in the strange behaviors of electrons in the microscopic world, which differ significantly from our common sense and daily experiences of the macroscopic world.The fields of physics explored in the book are quantum mechanics, superconductivity, electron microscopy, holography, magnetism, and unified theory — areas of the author's study using electron waves.A world-renowned expert in electron holography, the author promises the interested reader a fascinating ride through the quantum world of electron waves, accompanied by many colorful illustrations that delight the senses and captivate the imagination.