A process for preparing an electroluminescent film which comprises causing a substrate (5) held at a high tempe­rature to simultaneous contact with two kinds of vapors of (a) Group II element and a Group VI element or a compound (6) thereof capable of forming a Group II - VI compound semiconductor, and (b) a halide (12) of an element capable of acting as luminescent centers in a Group II - VI compound semiconductor, under the flowing of a hydrogen or inert gas (11), whereby a thin electroluminescent film comprising the Group II - VI compound semiconductor and containing the element forming the luminescent centers is formed on the surface of the substrate.