A semiconductor device includes a first storage unit including twin cells which are electrically rewritable and complementarily store 1-bit data based on a difference in a threshold voltage, a second storage unit including a memory cell which is electrically rewritable, data stored in the memory cell being erased when data in the twin cells is erased, at least one scrambler subjecting first data to a scramble processing by using scramble data to generate second data, a first write circuit which writes the second data into the twin cells in the first storage unit, a second write circuit which writes the scramble data into the memory cell in the second storage unit, and at least one descrambler subjecting the second data read from the first storage unit to a descramble processing by using the scramble data read from the second storage unit.