A light-emitting panel substrate for an active-matrix light-emitting panel in which a light-emitting element for each pixel emits light as a result of a current corresponding to a voltage supplied to a data line, including, in association with at least one pixel a current control element capable of controlling the current flowing in correspondence with the voltage supplied to the data line; a diode connected in series to the current control element; and a test line for leading the current flowing through the diode for testing.