A semiconductor device includes a first memory; and a voltage adjusting portion configured to receive a first voltage, a second voltage higher than the first voltage, and a third voltage higher than the second voltage. The first memory includes: a memory cell configured to be connected to a word line and a bit line, a word-line driving circuit configured to drive the word line, and a sense amplifier configured to sense information stored in the memory cell. The voltage adjusting portion includes: a voltage modifying circuit configured to step down or boost up the third voltage at a predetermined mode to generate a fourth voltage higher than the second voltage, and supply the fourth voltage to the sense amplifier or the word-line driving circuit.