Both ac and dc orange (580 nm) electroluminescence (EL) are reported for thin films of ZnF2 : Mn sandwiched between SiO semi‐insulating films. All layers are formed by vacuum evaporation and no postdeposition annealing is required. Unique power input and efficiency‐vs‐frequency characteristics are observed, in part due to the 0.1‐s lifetime of excited Mn in ZnF2; hysteresis in the brightness‐voltage characteristic occurs. The brightness and power efficiency are found to be, respectively, 10 f L and 0.5% under suitable operating conditions.