A lighting device comprising: a first case comprising a first bottom plate; a first and second side wall substantially vertically extending from both ends of the first bottom plate; a first louver inclined from the end of the first side wall with respect to a surface of the first side wall; a second louver inclined from the end of the second side wall with respect to a surface of the second side wall; a first light emitter seated on the first bottom plate; and a first diffuser being spaced apart from the first light emitter and having its both ends arranged at the ends of the first side wall and the second side wall; a second case comprising a second bottom plate; a third and fourth side wall substantially vertically extending from both ends of the second bottom plate; a third louver inclined from the end of the third side wall with respect to a surface of the third side wall; a fourth louver inclined from the end of the fourth side wall with respect to a surface of the fourth side wall; a second light emitter seated on the second bottom plate; and a second diffuser being spaced apart from the second light emitter and having its both ends arranged at the ends of the third side wall and the fourth side wall;, a bracket coupled to the second louver of the first case and the third louver of the second case, wherein each of the first case and second case comprises a first bracket coupler, wherein the first bracket coupler of the first case is disposed at the end of the second louver of the first case, and the first bracket coupler of the second case is disposed at the end of the third louver of the second case, and wherein the bracket is coupled to the first bracket coupler of the first case and the first bracket coupler of the second case. a first case comprising a first bottom plate; a first and second side wall substantially vertically extending from both ends of the first bottom plate; a first louver inclined from the end of the first side wall with respect to a surface of the first side wall; a second louver inclined from the end of the second side wall with respect to a surface of the second side wall; a first light emitter seated on the first bottom plate; and a first diffuser being spaced apart from the first light emitter and having its both ends arranged at the ends of the first side wall and the second side wall; a first bottom plate; a first and second side wall substantially vertically extending from both ends of the first bottom plate; a first louver inclined from the end of the first side wall with respect to a surface of the first side wall; a second louver inclined from the end of the second side wall with respect to a surface of the second side wall; a first light emitter seated on the first bottom plate; and a first diffuser being spaced apart from the first light emitter and having its both ends arranged at the ends of the first side wall and the second side wall; a second case comprising a second bottom plate; a third and fourth side wall substantially vertically extending from both ends of the second bottom plate; a third louver inclined from the end of the third side wall with respect to a surface of the third side wall; a fourth louver inclined from the end of the fourth side wall with respect to a surface of the fourth side wall; a second light emitter seated on the second bottom plate; and a second diffuser being spaced apart from the second light emitter and having its both ends arranged at the ends of the third side wall and the fourth side wall;, a second bottom plate; a third and fourth side wall substantially vertically extending from both ends of the second bottom plate; a third louver inclined from the end of the third side wall with respect to a surface of the third side wall; a fourth louver inclined from the end of the fourth side wall with respect to a surface of the fourth side wall; a second light emitter seated on the second bottom plate; and a second diffuser being spaced apart from the second light emitter and having its both ends arranged at the ends of the third side wall and the fourth side wall;, a bracket coupled to the second louver of the first case and the third louver of the second case, wherein each of the first case and second case comprises a first bracket coupler, wherein the first bracket coupler of the first case is disposed at the end of the second louver of the first case, and the first bracket coupler of the second case is disposed at the end of the third louver of the second case, and wherein the bracket is coupled to the first bracket coupler of the first case and the first bracket coupler of the second case.