A lighting device may be provided that includes a light emitting module including a substrate and a light emitting device disposed on the substrate; and a case receiving the light emitting module therewithin and including an upper case disposed on the substrate and a lower case in which the substrate is disposed. The lower case includes a seating portion which is coupled to a heat sink. The seating portion is either a projection projecting outward from the outer surface of the lower case or a recess which is formed by digging inward the outer surface of the lower case.