A display device includes a pixel area including pixels arranged in a matrix and having a horizontal resolution of 350 ppi or more and a color filter layer overlapping with the pixel area. The pixels each include a first transistor whose gate is electrically connected to a scan line and whose one of a source and a drain is electrically connected to a signal line; a second transistor whose gate is electrically connected to the other of the source and the drain of the first transistor and whose one of a source and a drain is electrically connected to a current-supplying line; and a light-emitting element electrically connected to the other of the source and the drain of the second transistor. The first and second transistors each have a channel formation region including a single crystal semiconductor.