To provide a highly reliable semiconductor device including an oxide semiconductor. Further to provide a highly reliable light-emitting device including an oxide semiconductor. A second electrode sealed together with a semiconductor element including an oxide semiconductor hardly becomes inactive. A hydrogen ion and/or a hydrogen molecule produced by reaction of the active second electrode with moisture remaining in the semiconductor device and/or moisture entering from the outside of the device increase the carrier concentration in the oxide semiconductor, which causes a reduction in the reliability of the semiconductor device. An adsorption layer of a hydrogen ion and/or a hydrogen molecule may be provided on the other surface side of the second electrode having one surface in contact with the organic layer. Further, an opening which a hydrogen ion and/or a hydrogen molecule passes through may be provided for the second electrode.