An illumination device is provided and includes a light guide; a light emitter facing the light guide; a wiring substrate provided on the light emitter and electrically connected to the light emitter; and a frame surrounding the light guide and the light emitter, wherein the wiring substrate has a first edge and a second edge which extend in a first direction, and a third edge which connects the first edge and the second edge, the frame has a fourth edge facing the third edge, the third edge and the fourth edge are spaced apart from each other and form a trench which communicates with an outside of the illumination device, and the trench has a curved portion in plan view.