Electroluminescence (EL) properties of AlN:Tb thin film EL device (TFELD) prepared on a glass substrate by a rf-magnetron sputtering method have been studied. The AlN:Tb emission layer consists of hexagonal (110)-oriented poly-crystals of AlN with a high transparency in visible region. Four emission peaks originating from 5D4 → 7Fj (j = 6, 5, 4, 3) transitions of Tb3+ were found in both photoluminescence (PL) and EL spectra of the AlN:Tb thin film. The peak emission intensity of the 5D4 → 7F6 transitions is almost the same magnitude with that of the 5D4 → 7F5 transitions, being largely different from the intensity ratio of Tb3+in other host materials.