An MRI apparatus includes a data acquisition system, a charge/discharge element and a power control unit. The data acquisition system acquires nuclear magnetic resonance signals from an imaging region by performing a scan. The charge/discharge element is a part of an electric power system of the MRI apparatus, and is charged with external electric power. The power control unit controls the electric power system in such a manner that at least one unit excluding the data acquisition system is supplied with electric power from the charge/discharge element.