An output current from each output terminal (X) of an organic EL panel driving circuit (10) to each column pin or each data line is selected by a switch scanning circuit (3) by sequentially turning on a plurality of switch circuits (SW) and is supplied to a resistor (RaRb) selected by a selector (2). A voltage value converted by the resistor is outputted to an external to compare the voltage value, and a current value of the output current from each output terminal (X) to each column pin or each data line is correct or not is tested. Thus, test time can be shortened. |