The fill of a self-extinguishing gas probe starter for an electrodeless high intensity discharge lamp includes a starter fill component which has a relatively low vapor pressure and is substantially inert in the starter fill at ambient temperatures, but which component vaporizes and becomes electronegative as the temperature of the lamp increases, so that the starter fill component attaches electrons of the starting discharge in the gas probe starter and thereby extinguishes the starting discharge after initiation of the arc discharge in the arc tube. As a result, the flow of currents between the gas probe starter and the arc tube, which would otherwise have a detrimental effect on the arc tube wall, is avoided.