When a phase-change element that can transition between a reset state (amorphous state) and a set state (crystalline state) is to be caused to transition to the reset state, a first pulse having a first voltage is applied to the phase-change element. The first voltage is higher than the threshold voltage in the reset state, and can cause current to flow that corresponds to an amount of generated heat required for placing the element in the reset state. When the phase-change element is to be caused to transition to the set state, a second pulse having a second voltage and the same time width as the first pulse is applied to the phase-change element. The second voltage that is higher than the threshold voltage but lower than the first voltage, and can cause only a current to flow that does not attain the necessary amount of generated heat.