An ignition control apparatus for an engine; in particular, an engine having two or more igniter plugs per cylinder energized by a electric power source, comprises a voltage detector for detecting a voltage of the electric power source, and a controller configured to effect initial combustion using both igniter plugs, to determine whether the voltage is lower than a first threshold voltage, and to effect further combustion using one of the igniter plugs when the voltage detected by the voltage detector is determined to be lower than the first threshold voltage.