To provide a lamp regulator and a lamp lighting device capable of preventing mislighting at a time of energizing lamp breakage at a time of abnormality.

When power is applied, if a voltage of a capacitor C is lower than a reference voltage, a control circuit II turns off a switch element Q2. A current from a diode bridge DB flows to the capacitor C via a circuit of a resistance Rb which is a second current route by-passing a lamp, whereby the capacitor C is charged. Because of this, mislighting at a time of energizing can be avoided. If a voltage Vc of the capacitor C becomes equal to or higher than the reference voltage, the control circuit II turns on the switch element Q2. A control circuit I detects a lamp current IL by means of a lamp voltage and ON/OFF controls a switch Q1 in a synchronizing manner with a power source frequency, and the lamp LAMP is lighted by a charging/discharging current of the capacitor C. If the voltage Vc of the capacitor C falls below the reference voltage, the control circuit II turns off the switch Q2 whereby breakage of the lamp can be prevented.