One hundred years ago Heike Kamerlingh Onnes arrived to one of the most important breakthroughs of 20th century physics - he discovered superconductivity. His finding as in many other cases in the history of science had been a result of use of a very new experimental technique. He used the cryogenic equipment in his Leiden's laboratory with the liquid helium cryocooler and measured electrical properties of metals near the absolute zero temperature. When cooled down to extremely low temperatures, near 4 Kelvin, very pure mercury suddenly lost its electrical resistance completely. Many major physicists of 20th century, experimentalists as well as theorists, devoted their life efforts to exploration of the mysterious properties of superconductors. Superconductivity has been shown to be one of the rare cases where quantum physics is observed on a macroscopic scale. Many chemical elements and thousands of compounds have been found to be superconducting. Fifty years after the discovery important practical applications such as strong magnets for laboratories and magnetic-resonance-imaging in hospitals came to the market. But more than seventy five years the superconducting materials had been functioning only at extreme cold, below 23 K (-250°C). In 1986 the "hightemperature superconductor's" era started with materials superconducting at -100°C. This paper surveys the history and the latest research into one of today's most fascinating physics and promising technologies., Peter Samuely., and Obsahuje bibliografii