A lighting device, wherein the effectivity is increased and allows maintaining a simple manufacturing process, comprises: a housing having a longitudinal direction, the housing comprising: reflective side walls extending in the longitudinal direction, a first cavity disposed between the reflective side walls, and an opening of the first cavity for the passage of light from the first cavity; LEDs, each having a light-emitting face and side faces, wherein the LEDs are arranged on interposers for providing electrical connection of the LEDs, wherein the LEDs are arranged in the first cavity such that the LEDs are at least partially arranged along the longitudinal direction of the housing; and a reflection element that covers a side of the interposers facing the opening, wherein the reflection element surrounds the LEDs on the side faces, and is configured as strip comprising through holes in which the LEDs are arranged.