Cs3Sb photocathode was formed by newly developed process and successive in-situ lightingdevices were fabricated in a process chamber. R, G, and B phosphors were applied on the anode plate,respectively. Major parameters such as brightness, power consumption, and efficacy were measured. Thewavelength of LED excitation source was 450 nm. Both high power and low power modes were appliedin the measurement. Measurement values were clearly differentiated by the voltage application modes. The measured values of each parameter was good enough to be applied for general lighting source. Theresults showed that Cs3Sb photocathode formed in atmospheric conditions was functioning as good as thephotocathode formed in UHV conditions, and thus it could be applied to advanced lighting devices.