A lighting device comprising: a direct current converter including at least an inductor, a switching unit and a diode and being configured to output an energy accumulated in the inductor to an LED load via the diode by using an input from a direct current power source when the switching unit is turned off; a load voltage detection unit connected to the LED load to detect a load voltage (V LED) of the LED load; an abnormality determining unit configured to determine an abnormality when the load voltage (V LED) detected by the load voltage detection unit is equal to or less than a preset threshold voltage; and an output control unit coupled to the abnormality determining unit and configured to drive the switching unit so that oscillation of the switching unit is stopped or the output of the direct current converter is decreased when the abnormality is determined by the abnormality determining unit; characterized in that the direct current converter further includes a resistor connected in parallel with the LED load, wherein one terminal of the resistor is connected to a high-potential side of the direct current power source, and the other terminal the resistor is connected to said one of the terminals of the LED load, and the load voltage detection unit is connected to said one of said terminals of the LED load for detecting the load voltage (V LED); wherein the load voltage detection unit includes first and second resistances (R1, R2) connected in series between said one of said terminals of the LED load to which the load voltage detection unit is connected, and a predetermined potential to provide a divided voltage (V b) at a connection point between said first and second resistances (R1, R2); wherein the load voltage detection unit further includes a PNP transistor and a third resistance; wherein the connection point is connected to the base of the PNP transistor to provide the divided voltage (V b) to the base of the PNP transistor; wherein one terminal of the third resistance is connected to the emitter of the PNP transistor and the other terminal of the third resistance is connected to a power supply voltage (Vcc); wherein the collector of the PNP transistor is connected to the predetermined potential; and wherein the voltage at the emitter of the PNP transistor and said one terminal of the third resistance is provided as a signal indicative of the load voltage (V LED) to the abnormality determining unit. a direct current converter including at least an inductor, a switching unit and a diode and being configured to output an energy accumulated in the inductor to an LED load via the diode by using an input from a direct current power source when the switching unit is turned off; a load voltage detection unit connected to the LED load to detect a load voltage (V LED) of the LED load; an abnormality determining unit configured to determine an abnormality when the load voltage (V LED) detected by the load voltage detection unit is equal to or less than a preset threshold voltage; and an output control unit coupled to the abnormality determining unit and configured to drive the switching unit so that oscillation of the switching unit is stopped or the output of the direct current converter is decreased when the abnormality is determined by the abnormality determining unit; characterized in that the direct current converter further includes a resistor connected in parallel with the LED load, wherein one terminal of the resistor is connected to a high-potential side of the direct current power source, and the other terminal the resistor is connected to said one of the terminals of the LED load, and the load voltage detection unit is connected to said one of said terminals of the LED load for detecting the load voltage (V LED); wherein the load voltage detection unit includes first and second resistances (R1, R2) connected in series between said one of said terminals of the LED load to which the load voltage detection unit is connected, and a predetermined potential to provide a divided voltage (V b) at a connection point between said first and second resistances (R1, R2); wherein the load voltage detection unit further includes a PNP transistor and a third resistance; wherein the connection point is connected to the base of the PNP transistor to provide the divided voltage (V b) to the base of the PNP transistor; wherein one terminal of the third resistance is connected to the emitter of the PNP transistor and the other terminal of the third resistance is connected to a power supply voltage (Vcc); wherein the collector of the PNP transistor is connected to the predetermined potential; and wherein the voltage at the emitter of the PNP transistor and said one terminal of the third resistance is provided as a signal indicative of the load voltage (V LED) to the abnormality determining unit.