Reverse bias voltage VM is applied to any one of self light emitting elements arranged on a light emitting panel 1 under detection mode. Current corresponding to weak current flowing to the element is supplied to a transistor Q3 by the operation of a current mirror circuit comprised of transistors Q1, Q2. The current mirror circuit is formed with the transistor Q3 as a control side current source transistor and transistors Q4 to Q7 as a controlled side current source transistor. The sizes of the controlled side current source transistors Q4 to Q7 are set to, for example, 1:2:4:8 with respect to the control side current source transistor Q3 so as to construct current amplifying means. Current value amplified by a current comparison type comparator 7 is compared with current value from a reference current source 8 and its output is latched by a latch circuit 9 and stored in a data register 10. If a weak current over a predetermined value flows when reverse bias voltage is applied to the self light emitting element, it is determined that a possibility that the self light emitting element turns into a light emission fault is high and notifying means is driven appropriately using data stored in the data register 10.