To provide a light-emitting element and a light-emitting device which can be designed and manufactured with redundancy. A light-emitting element of the invention includes a pair of electrode, and a layer containing a light-emissive substance between the pair of electrodes. The layer containing a light-emissive substance includes a layer containing a composite material, and the layer containing a composite material includes an organic compound and an inorganic compound. The concentration ratio of the organic compound to the inorganic compound changes periodically. The layer containing a composite maternal can be changed in electrical characteristics without changing the composition ratio of the organic compound to the inorganic compound in the layer or changing the kind of compounds used for the layer.