An objective of the present invention is to provide a switching device that shows two markedly different stable resistance characteristics reversibly and repetitively, and which is applicable to highly integrated nonvolatile memories.The present invention provides a switching device, which comprises a variable resistor element that has, between two electrodes, a metal-oxide thin-film comprising a single central metal element with a compositional variation; which is connected to a control circuit which can apply, between said two electrodes, a voltage or a current selected from among a voltage or a current of the first threshold or higher, a voltage or a current of the second threshold or lower whose absolute value is smaller than the absolute value of said first threshold, and a voltage or a current of the third threshold or lower whose absolute value is smaller than the absolute value of said second threshold; and in which the interelectrode resistance characteristic reversibly changes by a factor of 1,000 to 10,000 in the voltage or current region whose absolute value is equal to or below the third threshold.