An imaging device that has an image processing function and is capable of a high-speed operation is provided. The imaging device, which has an additional function such as image processing, can retain analog data obtained by an image capturing operation in a pixel and extract data obtained by multiplying the analog data by a predetermined weight coefficient. In the imaging device, some of potentials used for an arithmetic operation in pixels are generated by redistribution of charge with which wirings are charged. This enables an arithmetic operation to be performed at high speed with low power consumption, compared with the case where the potentials are supplied from another circuit to the pixels.