In an ignition system including an ignition distributor integrated with an ignition coil, an electrical conductor linking leakage magnetic flux of the ignition coil is arranged on the outer periphery of the coil of an electromagnetic pickup to have a current conducting path around the axis of the coil. An eddy current is induced in the conductor by the leakage magnetic flux to generate magnetic flux in the direction opposite to the leakage magnetic flux of the ignition coil by the eddy current, thereby reducing a noise voltage generated in the electromagnetic pickup.