This unique collection of papers by leading German scientists reviews recent accomplishments, presents new results and discusses possible future developments of superconducting quantum electronics and high Tc superconductivity. The three main parts of the book deal with fundamentals, sensitive detectors, and precision metrology. The book will be valuable to researchers and students at academic and industrial institutions who are interested in theory and precision experiments. New results reported include: correct equivalent circuits modelling superconducting electronic devices; exact solution of the Mattis-Bardeen equations describing perfectly various experiments for thin films; complete theoretical description and first experimental results for a new broad band spectrum analyzer; a new Josephson junction potentiometer allowing tracing of unknown voltage ratios back to well-known frequency ratios; and fast superconducting SQUID shift registers enabling the production of calculable noise power spectra in the microwave region.