To drive a light-emitting element of charge-injection type using an inorganic compound as a light-emitting material by improving the electrical conductivity of the light-emitting material.

A sulfide is used as a matrix. For increasing the electrical conductivity of the light-emitting material, a donor element is added to the light-emitting material. As the donor element, an element less than 0.3 eV in the energy gap between a donor level made by the donor element and the conduction band bottom is selected; wherein, if the matrix is zinc sulfide(ZnS), aluminum(Al), gallium(Ga), indium(In) or boron(B) is selected.