First rib layers made of an inorganic material are formed in first frame regions of a first glass substrate. First resin layers are formed in first product regions after the first rib layers are formed. First functional layers which include light emitting element layers as a result of luminance of each of unit pixels forming an image being controlled and sealing layers covering the light emitting element layers are formed on the first rib layers and the first resin layers. The first rib layers and the first functional layers are cut along lines passing through the first frame regions while avoiding the first product regions in order to separate the first product regions from each other. In the step of cutting the first rib layers and the first functional layers, the first rib layers and the sealing layers are cut.