A method of collectively producing display panels each having an outline a part of which is curved includes a bonded substrate forming process of bonding substrates in a pair one of which has thin film patterns and forming a bonded substrate 50, a layering process of layering multiple bonded substrates 50 via curing resin 60 and curing the curing resin 60, a grinding process of collectively grinding the substrates in a pair and the curing resin 60 that are outside the thin film pattern on each of the bonded substrates 50B that are layered on each other along the outline and collectively forming edge surfaces of the display panels each having the curved outline, and a separation process of separating each of the bonded substrates 50B that are layered on each other from the curing resin 60.