The invention reduces the resistance of a feed line in a display device (electro-optical device), and reduces the loss in the current supply to a light-emitting element, etc. In an electro-optical device including an electro-optical element and a driver circuit to drive the electro-optical element, a wiring board used for the electro-optical device includes a feed line film to supply the driver circuit with current to put the electro-optical element into operation; a signal line film to supply the driver circuit with a level signal to determine intensity of the current to be supplied to the electro-optical element; and an operation line film to supply the driver circuit with an operation instruction signal to instruct whether to put the electro-optical element into operation, and the feed line film constitutes an upper layer among the feed line film, the signal line film, and the operation line film.