A lighting device for a semiconductor light-emitting element comprising: a DC-DC converter for converting a DC current from a DC power source (Vdc) to supply a DC current to a semiconductor light-emitting element; and a dimming control part for controlling the DC-DC converter to adjust a magnitude of the current flowing to the semiconductor light-emitting element, wherein: the DC-DC converter comprises at least a switching element, an inductive element and a regenerative diode, and operates in a discontinuous mode in which energy stored from the DC power source (Vdc) into the inductive element in an ON period of the switching element is released through the regenerative diode in an OFF period of the switching element, and the switching element is turned on after completion of release of the energy in the inductive element; and the dimming control part comprises an output detecting part (5a, 5b) for detecting at least one of the current flowing to the semiconductor light-emitting element or a voltage applied to the semiconductor light-emitting element, and a feedback control part for adjusting an ON period of the switching element during the ON/OFF operation or for adjusting a period in which the ON/OFF operation of the switching element is intermittently stopped, so that said detected voltage and/or current value of the output detecting part (5a, 5b) approaches a target value, wherein the power supplied to the feedback control part is stopped and the ON period of the switching element is fixed to a minimum value when the dimming control level is lower than a predetermined value, a burst dimming control part for intermittently stopping an ON/OFF operation of the switching element when the dimming control level is lower than the predetermined value, thereby adjusting the current flowing to the semiconductor light-emitting element. a DC-DC converter for converting a DC current from a DC power source (Vdc) to supply a DC current to a semiconductor light-emitting element; and a dimming control part for controlling the DC-DC converter to adjust a magnitude of the current flowing to the semiconductor light-emitting element, wherein: the DC-DC converter comprises at least a switching element, an inductive element and a regenerative diode, and operates in a discontinuous mode in which energy stored from the DC power source (Vdc) into the inductive element in an ON period of the switching element is released through the regenerative diode in an OFF period of the switching element, and the switching element is turned on after completion of release of the energy in the inductive element; and the dimming control part comprises the DC-DC converter comprises at least a switching element, an inductive element and a regenerative diode, and operates in a discontinuous mode in which energy stored from the DC power source (Vdc) into the inductive element in an ON period of the switching element is released through the regenerative diode in an OFF period of the switching element, and the switching element is turned on after completion of release of the energy in the inductive element; and the dimming control part comprises an output detecting part (5a, 5b) for detecting at least one of the current flowing to the semiconductor light-emitting element or a voltage applied to the semiconductor light-emitting element, and a feedback control part for adjusting an ON period of the switching element during the ON/OFF operation or for adjusting a period in which the ON/OFF operation of the switching element is intermittently stopped, so that said detected voltage and/or current value of the output detecting part (5a, 5b) approaches a target value, wherein the power supplied to the feedback control part is stopped and the ON period of the switching element is fixed to a minimum value when the dimming control level is lower than a predetermined value, a burst dimming control part for intermittently stopping an ON/OFF operation of the switching element when the dimming control level is lower than the predetermined value, thereby adjusting the current flowing to the semiconductor light-emitting element.