A display device including a light source; a wavelength conversion member to convert a wavelength of light generated from the light source; a light guide member to guide the light converted by the wavelength conversion member; and an adhering member. In addition, the wavelength conversion member includes a first surface facing the light source; a second surface facing the light guide member; a top surface extending from the first surface to the second surface; and a bottom surface facing the top surface. Furthermore, the adhering member is disposed on the top surface and the bottom surface. Also, the wavelength conversion member includes a tube, the tube receives a sealing member, an air layer and a matrix therein, and the air layer is formed between the sealing member and the matrix.