A lighting device includes a board mounting a light source, a first hole provided in the board, a projecting part protruded inside the first hole from a periphery of the first hole, a light guide which receives a light emitted from the light source through a light receiving plane, and transmits the light from a light transmitting plane, and the first protrusion which is integrally formed in the light guide and is inserted into the first hole, wherein the projecting part presses a side of the first protrusion so that the board can move toward the light receiving plane.