The number of photolithography steps used for manufacturing a transistor is reduced to less than the conventional one and a highly reliable semiconductor device is provided. The present invention relates to a semiconductor device including a circuit including a transistor having an oxide semiconductor layer over a first substrate and a second substrate fixed to the first substrate with a sealant. A closed space surrounded by the sealant, the first substrate, and the second substrate is in a reduced pressure state or filled with dry air. The sealant surrounds at least the transistor and has a closed pattern shape. Further, the circuit is a driver circuit including a transistor having an oxide semiconductor layer.