A first level shifter outputs one of a first potential and a second potential lower than the first potential from an output terminal in accordance with the level of an input signal. A second level shifter outputs one of the first potential and a third potential lower than the second potential from an output terminal in accordance with the output potential from the first level shifter. A third level shifter outputs one of the first and second potentials from an output terminal in accordance with the level of the input signal. A first switching circuit selects the output voltage from the second level shifter when a high-speed operation is required such as in a read operation.