A lighting device for turning on light emitting elements, comprising: a rectifying unit adapted to rectify an AC voltage outputted from a power supply and output a ripple voltage; a partial smoothing circuit adapted to partially smooth a voltage in low voltage periods of the ripple voltage output from the rectifying unit; a power supply unit which has a switching element and adapted to convert an output voltage of the partial smoothing circuit into a predetermined DC voltage by switching on/off of the switching element to output the predetermined DC voltage; and a control unit adapted to control on/off of the switching element, wherein the partial smoothing circuit includes a first capacitor, a second capacitor, a first diode, a second diode, a third diode and a resistor, wherein the first diode is connected between a negative electrode of the first capacitor and a negative electrode of the second capacitor, a cathode of the first diode is connected to the negative electrode of the first capacitor; the third diode is connected between a positive electrode of the first capacitor and a positive electrode of the second capacitor, an anode of the third diode is connected to the positive electrode of the second capacitor; and the second diode and the resistor are connected in series between the negative electrode of the first capacitor and the positive electrode of the second capacitor, wherein an anode of the second diode is connected to the negative electrode of the first capacitor, one end of the resistor is connected to the cathode of the second diode, and the other end of the resistor is connected to the positive electrode of the second capacitor, wherein the power supply unit is adapted to supply a lighting power to a light source unit including one or more light emitting elements; wherein an input current of the partial smoothing circuit which is provided from the rectifying unit has at least two peak values, wherein the at least two peak values include a peak value occurring when charging the first capacitor and the second capacitor of the partial smoothing circuit, and characterized in that at least one of a resistance value of the resistor and a capacitance value of each of the first capacitor and the second capacitor is configured to render the peak value of the input current occurring when charging the first capacitor and the second capacitor of the partial smoothing circuit to be smaller than at least one of the rest of the at least two peak values of the input current, and in that, when an input power supplied to the power supply unit is 4 W to 10 W, the resistance value R0 [Ω] of the resistor is set to meet R0 ≥ 16 × C0 - 80 or the capacitance value C0 [μF] of each of the first capacitor and the second capacitor is set to meet C0 ≤ 5. a rectifying unit adapted to rectify an AC voltage outputted from a power supply and output a ripple voltage; a partial smoothing circuit adapted to partially smooth a voltage in low voltage periods of the ripple voltage output from the rectifying unit; a power supply unit which has a switching element and adapted to convert an output voltage of the partial smoothing circuit into a predetermined DC voltage by switching on/off of the switching element to output the predetermined DC voltage; and a control unit adapted to control on/off of the switching element, wherein the partial smoothing circuit includes a first capacitor, a second capacitor, a first diode, a second diode, a third diode and a resistor, wherein the first diode is connected between a negative electrode of the first capacitor and a negative electrode of the second capacitor, a cathode of the first diode is connected to the negative electrode of the first capacitor; the third diode is connected between a positive electrode of the first capacitor and a positive electrode of the second capacitor, an anode of the third diode is connected to the positive electrode of the second capacitor; and the second diode and the resistor are connected in series between the negative electrode of the first capacitor and the positive electrode of the second capacitor, wherein an anode of the second diode is connected to the negative electrode of the first capacitor, one end of the resistor is connected to the cathode of the second diode, and the other end of the resistor is connected to the positive electrode of the second capacitor, wherein the power supply unit is adapted to supply a lighting power to a light source unit including one or more light emitting elements; wherein an input current of the partial smoothing circuit which is provided from the rectifying unit has at least two peak values, wherein the at least two peak values include a peak value occurring when charging the first capacitor and the second capacitor of the partial smoothing circuit, and at least one of a resistance value of the resistor and a capacitance value of each of the first capacitor and the second capacitor is configured to render the peak value of the input current occurring when charging the first capacitor and the second capacitor of the partial smoothing circuit to be smaller than at least one of the rest of the at least two peak values of the input current, and in that, when an input power supplied to the power supply unit is 4 W to 10 W, the resistance value R0 [Ω] of the resistor is set to meet R0 ≥ 16 × C0 - 80 or the capacitance value C0 [μF] of each of the first capacitor and the second capacitor is set to meet C0 ≤ 5.