A light generating device includes a body having discharge spaces generating light in response to a voltage signal, and electrodes providing the voltage signal to the discharge spaces. The discharge spaces are apart from each other and arranged substantially parallel with each other. The electrodes are disposed at external portions of the body. The body includes a first substrate, and a second substrate disposed on the first substrate. The second substrate includes space forming members and space dividing members. The discharge spaces are each formed between corresponding one of the space forming members and the first substrate. The space dividing members are each disposed between the adjacent space forming members. The space dividing members include connecting passages each connecting adjacent ones of the discharge spaces. A display device includes a display panel for displaying images using an image signal, a driving signal and light, the planar light generating device for providing the light to the display panel, and an inverter for generating the voltage signal to the planar light generating device.