A light emitting module includes a module body, a light source unit disposed at one side of the module body, an air hole formed through the module body from one side of the module body to the other side of the module body for allowing air to flow therethrough, and an optical cover for covering the light source unit. The optical cover has a cover hole at a location corresponding to the air hole. The optical cover includes a partition wall protruding downward from a bottom of the optical cover such that the partition wall is inserted into one side of the module body to seal the light source unit, and a pair of fitting wings protruding outward from opposite ends of the optical cover such that the fitting wings are inserted into the module body.