A method of manufacturing a display device includes a cell forming step of forming a predetermined number of cells on a mother substrate, a first polishing step of chemically polishing an outer surface of the mother substrate with use of a predetermined polishing solution, a dividing step of dividing the chemically polished mother substrate so as to include a number of cells, which is less than the predetermined number, and a second polishing step of mechanically polishing the outer surface of the divided mother substrate with use of a solid polishing agent.