A wiring substrate includes a substrate, an insulating film stacked on the substrate, an anode pad stacked on a first surface of the insulating film and electrically coupled to an anode of an inorganic light-emitting diode, a cathode pad stacked on the first surface of the insulating film and electrically coupled to a cathode of the inorganic light-emitting diode, and an auxiliary pad provided to the first surface of the insulating film and having electrical conductivity. The auxiliary pad is disposed in a floating state near an end of the anode pad and the cathode pad.