A magnetic resonance imaging device according to an embodiment includes a gradient amplifier, a battery, a detector, and a battery controller. The gradient amplifier supplies electric power to the gradient coil. The battery is charged with electric power that is supplied from the power supply. The detector detects a high power output request on the gradient amplifier. The battery controller controls to supply electric power charged in the battery in addition to electric power supplied from the power supply to the gradient amplifier when the high power output request is detected.