PURPOSE: To keep up operation for a certain period time, by discharging the energy of a superconductive coil with a resistance when the power supply to a superconductive electromagnetic pump makes a sudden stop which is equipped with a superconductive coil to generate magnetic field to a conductive fluid and with a circuit to cause the current to flow.

CONSTITUTION: Magnetic field is generated as shown as an arrowhead B to conductive fluid 1 flowing through inside a duct 2 with a superconductive coil 3 from a power source E1 and to the electrodes 6 at both ends inside the duct 2 the current is caused to flow from a power source E2 to constitute a superconductive electromagnetic pump. When the power supply makes a sudden stop, an output signal of a current detector 7 is sent to a changeover relay 8 and a changeover switch 9 is changed over, by which the energy of the superconductive coil 3 is sent to the conductive fluid 1 inside the duct 2 through a resistance R, attenuating gradually. The operation of the pump is thereby kept up for a certain period of time even if the power supply is suddenly stopped, so that the reliability will be improved.