A surface light source has a body including a first substrate, a second substrate facing with the first substrate, and a space-dividing member. The first substrate has first fluorescent patterns to convert an invisible ray into a visible ray. The first fluorescent patterns are formed in parallel by a first interval. The space-dividing member is interposed between the first and second substrates to form a discharge space. The space-dividing member has a width less than the first interval to emit the visible ray between the space-dividing member and the first fluorescent patterns. A power supply member generates the invisible ray in the discharge space. Thus, the surface light source enhances brightness of the visible ray emitted from the body.