The invention provides a lighting power and a lighting device for inhibiting changes of the brightness caused by the distortion of an input voltage. According to one embodiment, a lighting light source including a constant current element and a voltage-dividing resistor is provided. The constant current element comprises a first main electrode, a second main electrode series-connected with respect to a lighting light source, and a control electrode for controlling a current flowing between the first main electrode and the second main electrode, and controls a current supplied to the lighting light source. The voltage-dividing resistor is parallel-connected with respect to the lighting light source and connected to the control electrode, and inputs a voltage obtained by division of a voltage of the lighting light source to the control electrode.