A semiconductor device including a capacitor whose charge capacity is increased while improving the aperture ratio is provided. Further, a semiconductor device which consumes less power is provided. A transistor which includes a light-transmitting semiconductor film, a capacitor in which a dielectric film is provided between a pair of electrodes, an insulating film which is provided over the light-transmitting semiconductor film, and a first light-transmitting conductive film which is provided over the insulating film are included. The capacitor includes the first light-transmitting conductive film which serves as one electrode, the insulating film which functions as a dielectric, and a second light-transmitting conductive film which faces the first light-transmitting conductive film with the insulating film positioned therebetween and functions as the other electrode. The second light-transmitting conductive film is formed over the same surface as the light-transmitting semiconductor film of the transistor and is a metal oxide film containing a dopant.