A memory element includes an insulating substrate; a first electrode and a second electrode on the insulating substrate; and an inter-electrode gap portion that causes a change in resistance value between the first and second electrodes. Applied to the memory element from a pulse generating source is a first voltage pulse for shifting from a predetermined low-resistance state to a predetermined high-resistance state, and a second voltage pulse for shifting from the high-resistance state to the low-resistance state through a series-connected resistor, by which current flowing to the memory element after the change to a low resistance value is reduced. When shifting from the high to the low-resistance state, a voltage pulse is applied such that an electrical resistance between the pulse generating source and the memory element becomes higher than the electrical resistance shifting from the low to the high-resistance state.