A semiconductor device having a light sensing function and including a high-resolution display portion is provided. The semiconductor device includes a plurality of pixels, and the pixels each include first and second light-receiving devices, first to fifth transistors, a capacitor, and a first wiring. One electrode of the first light-receiving device is electrically connected to the first wiring, and the other electrode is electrically connected to one of a source and a drain of the first transistor. One electrode of the second light-receiving device is electrically connected to the first wiring, and the other electrode is electrically connected to one of a source and a drain of the second transistor. The other of the source and the drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor. The other of the source and the drain of the first transistor is electrically connected to one electrode of the capacitor, one of a source and a drain of the third transistor, and a gate of the fourth transistor.