Applications of superconductivity in electronics are mainly based on the Josephson effect. After an introduction to the Josephson effect, its applications in computer circuits and in magnetometers will primarily be described. Computer circuits with Josephson junctions are of interest because they promise to have lower power consumption and shorter switching times than today's semiconductor circuits. A realized memory cell is briefly discussed. Magnetometers are based on superconducting rings incorporating one or two Josephson junctions. They allow extremely sensitive and precise measurements of magnetic fields and have been applied, for instance, in biology and geology. Other applications of the Josephson effect such as in voltage standards and for submillimeter microwave devices are also mentioned. Most of these applications use liquid helium cooling. The heat dissipation is in the range from mW to W so that requirements for refrigerating systems are modest. © 1978.