A power supply potential and a ground potential are supplied to a test-use power supply pad and a test-use ground pad, respectively. The power supply potential supplied to the test-use power supply pad is transferred to power supply lines and then to each circuit block via a test-use power supply line and a potential transfer circuit including a diode device. A voltage drop is caused by each of the diode devices. To cope with the voltage drop, however, respective sizes of the diode devices and resistance components of the potential transfer circuits are configured so that a uniform voltage drop is generated at each of the power supply lines.