A calibration circuit includes: a replica buffer that drives a calibration terminal; a pre-emphasis circuit connected in parallel to the replica buffer; and an up-down counter that changes impedances of the replica buffer and the pre-emphasis circuit. A replica control circuit causes the replica buffer to conduct based on an impedance code, and a pre-emphasis control circuit causes the pre-emphasis circuit to conduct in an initial stage of a conducting period of the replica buffer. Thereby, even when an external resistor is shared among a plurality of semiconductor devices, for example, a voltage appearing in the calibration terminal can be stabilized at a higher speed.