A peripheral circuitry is provided adjacent to a memory array and conducts read and write operations from and to the memory array. A power supply voltage line and a ground line for supplying an operating voltage to the peripheral circuitry supply a power supply voltage and a ground voltage, respectively. The power supply voltage line and the ground line are arranged so that a magnetic field generated by a current flowing through the power supply voltage line and a magnetic field generated by a current flowing through the ground line cancel each other in the memory array.