A light emitting apparatus includes a light source block with semiconductor light sources connected in series to each other. A resistor is connected in parallel with one or more of the semiconductor light sources and is connected to two detecting target portions in portions linked to respective electrodes of the semiconductor light sources. A ground fault detecting circuit is connected to one of the two detecting target portions disposed on a ground potential side. The light source block has one of its terminals connected to a power supply and its other terminal grounded. By detecting a change in the voltage through the ground fault detecting circuit, a ground fault can be detected.