BaAl2S4:Eu thin-film EL device using a new blue emitting EL phosphor was prepared by the two targets pulse-electron-beam evaporation. The maximum luminance level was 65 cd/m2 under the 50 Hz pulse voltage. The EL spectrum had blue emission with a peak around 470 nm due to the transition for Eu2+ ion. The CIE color coordinates of BaAl2S4:Eu EL device were x = 0.12 and y = 0.10. The performance of blue-emitting BaAl2S4:Eu EL devices is shown to be sufficient for commercial color EL display in color purity and luminance level.