An object is to improve the aperture ratio of a semiconductor device. The semiconductor device includes a driver circuit portion and a display portion (also referred to as a pixel portion) over the same substrate. The driver circuit includes a channel-etched thin film transistor for driver circuit and a driver circuit wiring formed using metal. Source and drain electrodes of the thin film transistor for the driver circuit are formed using a metal. A channel layer of the thin film transistor for the driver circuit is formed using an oxide semiconductor. The display portion includes a bottom-contact thin film transistor for a pixel and a display portion wiring formed using an oxide conductor. Source and drain electrode layers of the thin film transistor for the pixel are formed using an oxide conductor. A semiconductor layer of the thin film transistor for the pixel is formed using an oxide semiconductor.