To provide a small-sized, economical short circuit current suppressing device, which suppresses current in the short circuit with reliability as well as ensures low-reactance characteristic and system stability during steady state, and allows for the adoption of high-speed re-closing system required for high- voltage systems.

This alternating current suppressing device is provided with a first coil 3 and a second coil 4, series-connected with each other and wounded in such a direction that magnetic fluxes produced by passage of alternating current cancel out each other, a nonlinear resistor 5 parallel-connected with the second coil 4, and a short-circuit switch 6 parallel-connected with the non- linear resistor 5. When a short circuit current is passed, the nonlinear resistor 5 is actuated to let the current through it, and the device is provided with a reactance of a large value close to the self reactance of the first coil 3 and suppresses short circuit currents.