An ignition unit for a turbojet engine, including: an electrical power supply, a single control channel to receive a control signal from a computer, a main sparkplug ignition channel to energize at least one main sparkplug of a main combustion chamber, and an afterburner sparkplug ignition channel to energize at least one afterburner sparkplug of an afterburner chamber. The ignition unit is configured, in response to pulsed controls on the single control channel, to selectively activate the main sparkplug ignition channel or the afterburner sparkplug ignition channel.