A semiconductor device with reduced power consumption that can perform a product-sum operation is provided. The semiconductor device includes first and second circuits, and the second circuit includes first and second switches, a current/voltage converter circuit, and a first transistor. The first circuit is electrically connected to a first terminal of the second circuit; a first terminal of the first switch is electrically connected to the first terminal of the second circuit; a second terminal of the first switch is electrically connected to an input terminal of the current/voltage converter circuit; an output terminal of the current/voltage converter circuit is electrically connected to a first terminal of the first transistor; a second terminal of the first transistor is electrically connected to a first terminal of the second switch; and a second terminal of the second switch is electrically connected to a second terminal of the second circuit. The first circuit has a function of retaining a plurality of pieces of first data and a function of making a current in an amount responsive to the sum of products of the plurality of pieces of first data and a plurality of pieces of second data flow to the first terminal of the second circuit when the plurality of pieces of second data are input to the first circuit.