The invention has for its object to provide a phosphor thin film which can dispense with any filter and has satisfactory color purity, is particularly well fit for RGB full-color Els, and simplifies a full-color EL panel production process, thereby providing a phosphor thin film which is less susceptible to luminance variations and can be produced in improved yields and so at lower costs and its fabrication process as well as an EL panel. This is achieved by the provision of a phosphor thin film comprising a matrix material containing as a main component an alkali earth aluminate that is an oxide, with sulfur added to the matrix material, and further containing an element that provides a luminescentce center.