A head lamp device for a vehicle includes a DC power source, a diode array having a plurality of series-connected light emitting diodes and a current control circuit that supplies driving current to the diode array. The current control circuit is constituted of a current supply circuit, a voltage measuring circuit, a comparing circuit that compares the voltage drop with a reference value, a judging circuit for judging that there is a short-circuiting at any of the light emitting diodes based on the comparison by the comparing circuit, and a display unit for displaying an alarm when the judging circuit judges that there is a short-circuiting.