Data corrupted by a soft error is recovered. A storage device includes a first memory cell, a second memory cell, a sense circuit electrically connected to the first memory cell through a first sense line and to the second memory cell through a second sense line, a digital-analog converter circuit electrically connected to the first memory cell and the second memory cell through a bit line, and an analog-digital converter circuit. The digital-analog converter circuit has a function of applying voltages as first signals to the first memory cell and the second memory cell. Even when a soft error occurs in the first memory cell or the second memory cell, the storage device has a function of recovering data corrupted by the soft error because the sense circuit selects and outputs a higher one of the voltages applied to the first memory cell and the second memory cell.