A discharge lamp lighting device comprising: a power conversion part for outputting AC power by receiving DC power; a starting part connected, along with a discharge lamp (La), between output ends of the power conversion part so as to generate a high voltage for starting the discharge lamp (La); and a control part for controlling the power conversion part, wherein after performing a starting operation to start the discharge lamp (La) by a high voltage generated in the starting part and before starting a normal operation, the control part performs, in starting the discharge lamp (La), an electrode heating operation to cause the power conversion part to output AC power to the discharge lamp (La) for maintaining lighting of the discharge lamp (La), wherein the electrode heating operation makes a frequency outputted from the power conversion part higher than that during the normal operation over a predetermined period of time in order to heat each electrode of the discharge lamp (La), characterized in that the discharge lamp lighting device including a symmetry determination part for determining whether or not an output current (Ila) outputted from the power conversion part to the discharge lamp (La) is positive/negative symmetrical, and the control part causing, in finishing the electrode heating operation, transition to the normal operation upon determination of the output current (Ila) as being positive/negative symmetrical by the symmetry determination part or, upon determination of the output current (Ila) as being positive/negative asymmetrical by the symmetry determination part, the electrode heating operation to be performed again to follow a restarting operation modified compared with the starting operation, in order to reduce a difference in the output current (Ila) between polarities. a power conversion part for outputting AC power by receiving DC power; a starting part connected, along with a discharge lamp (La), between output ends of the power conversion part so as to generate a high voltage for starting the discharge lamp (La); and a control part for controlling the power conversion part, wherein after performing a starting operation to start the discharge lamp (La) by a high voltage generated in the starting part and before starting a normal operation, the control part performs, in starting the discharge lamp (La), an electrode heating operation to cause the power conversion part to output AC power to the discharge lamp (La) for maintaining lighting of the discharge lamp (La), wherein the electrode heating operation makes a frequency outputted from the power conversion part higher than that during the normal operation over a predetermined period of time in order to heat each electrode of the discharge lamp (La), the discharge lamp lighting device including a symmetry determination part for determining whether or not an output current (Ila) outputted from the power conversion part to the discharge lamp (La) is positive/negative symmetrical, and the control part causing, in finishing the electrode heating operation, transition to the normal operation upon determination of the output current (Ila) as being positive/negative symmetrical by the symmetry determination part or, upon determination of the output current (Ila) as being positive/negative asymmetrical by the symmetry determination part, the electrode heating operation to be performed again to follow a restarting operation modified compared with the starting operation, in order to reduce a difference in the output current (Ila) between polarities.