PURPOSE: To prevent a misfire from occurring during rapid acceleration or the like by providing a rapid discharge circuit discharging a condenser for a preset time after the first angle position is detected in an engine controlling the ignition timing in accordance with two angle position signals.

CONSTITUTION: An internal combustion engine is provided with pickups 1, 2 detecting the first and second angle positions θ1, θ2, a one-shot multivibrator 4 generating an output signal in a preset time TM in response to the output from an FF 3 when the angle position θ1 is detected, and a charge circuit charging in proportion to the time after the TM time has elapsed and before the angle position θ2 is detected. This charge circuit is constituted with an NAND circuit 5, transistor Tr 6, and condenser 10. A discharge circuit is also provided discharging the condenser 10 through a Tr 9 for a constant time after the angle position θ2 is detected. Furthermore, a rapid discharge circuit made of a Tr 14 is provided rapidly discharging the condenser 10 after the angle position θ1 has been detected and before the TM time elapses.