A display device comprising: a substrate; a plurality of display elements disposed on the substrate; and a diffraction pattern layer disposed on a path of light emitted from the plurality of display elements. The diffraction pattern layer comprises a plurality of diffraction patterns which is disposed with a predetermined pitch, and the plurality of diffraction patterns do not overlap the plurality of display elements; and when a width of a cross section of each of the plurality of diffraction patterns is defined as a length of each diffraction pattern, the predetermined pitch and the length of each diffraction pattern satisfy the following inequation: 0.4≤d1/DP1