PURPOSE: To enable to prevent excess rotation of an internal combustion engine without providing the additional harness for a vehicle body, by detecting the engine speed in an igniting apparatus, and interrupting current supply to an ignition coil at the time of high-speed operation of the engine.

CONSTITUTION: When the engine speed becomes higher than a predetermined value, a rotation detector 9 produces a rotation signal. An ignition stopping circuit 10 is furnished with the rotation signal and ignition signals and produces an ignition stop signal in synchronism with the ignition signals. Further, a by- pass circuit 8 is operated in response to the ignition stop signal and by-passes and earthes ignition pulses afforded from an ignition pulse circuit 2 to a switching circuit 3. With such an arrangement, it is made unnecessary to provide the additional harness for a vehicle body for transmitting the rotation signal.