Preface.- Theoretical Background of Quantum Metrology.- Measurements, Standards and Systems of Units.- The Revised SI System of Units.- Quantum Voltage Standards.- SQUID Detectors of Magnetic Flux.- Quantum Hall Effect and the Resistance Standard.- Quantization of Electrical Conductance and Thermal Conductance in Nanostructures.- Single Electron Tunneling.- Atomic Clocks and Time Scales.- Standards and Measurements of Length.- Satellite Navigation Systems.- Scanning Probe Microscopes.- New Standards of Mass.