A memory includes a first word line which is connected to a control gate electrode of a first memory cell, a second word line which is connected to a control gate electrode of a second memory cell, a potential transfer line which is connected to both of the first and second word lines, a first N-channel MOS transistor which is connected between the first word line and the potential transfer line, and a second N-channel MOS transistor which is connected between the second word line and the potential transfer line. A control circuit supplies a first potential with a plus value to a semiconductor substrate, and supplies a second potential with the plus value lower than the first potential to the potential transfer line, to turn the first N-channel MOS transistor on, and to turn the second N-channel MOS transistor off, in erasing data of the first memory cell.