To provide a test method of a short-circuited pixel of an organic EL panel capable of easily and simply test the short-circuited pixel.

A direct current voltage for testing the short-circuited pixel, generated at a direct current source 18B, is impressed between a plurality of positive electrodes 13 exposed at the side end part of the organic EL panel 11 and a plurality of negative electrodes 17 with a polarity reversed from that at the light emission, namely, the voltage is impressed by reversing the positive side and negative side. As the voltage with reversed polarity is impressed, current does not flow through the normal pixels G and ammeters 21, 22 do not work. On the contrary, when a short-circuited pixel exists, as the current of the direct current source 18B flows, the existence of the short-circuited pixel and its coordinate can be detected with the two ammeters 21, 22.