A data semiconductor device with a long retention time is provided. The semiconductor device includes a first transistor, a second transistor, a ferroelectric capacitor, a first capacitor, and a memory cell. Note that the memory cell includes a third transistor. A first gate of the first transistor is electrically connected to a first terminal of the ferroelectric capacitor, and a first terminal of the first transistor is electrically connected to a second gate of the first transistor and a first terminal of the second transistor. A second terminal of the second transistor is electrically connected to a second terminal of the ferroelectric capacitor and a first terminal of the first capacitor. A back gate of the third transistor is electrically connected to the first terminal of the first transistor. In the above structure, the threshold voltage of the third transistor can be increased by supplying a negative potential to the first terminal of the first transistor.