A thunderstorm detector for solving the technical problems of detecting an electric discharge of a far-off thunderstorm on the basis of the change in the magnetic field strength in the atmosphere. A parallel oscillating (tuned, resonant) circuit (1) having a ferrite core (3) is used as sensor. An amplifier (5) amplifies the output voltage of the parallel oscillating circuit (1). A square-wave pulse shaper (7) shapes the output voltage of the amplifier (5). A display circuit (9) provides a display. <IMAGE>
