Ignition apparatus for internal combustion engine

In an ignition apparatus (engine igniter) 1, when a spark-discharge duration time Tc calculated on the basis of operation conditions of an internal combustion engine has elapsed after generation of spark discharge by an ignition coil 13, an electricity-supply resumption circuit 51 is operated in order to resume supply of primary current i1 to a primary winding L1, to thereby interrupt the spark discharge. Further, a signal processing control circuit 23 performs electricity-supply-start timing delay control processing in order to delay the timing of supplying electricity to the primary winding L1 in accordance power source voltage, to thereby maintain the magnetic flux energy accumulated in the ignition coil 13 at a substantially constant level. With this apparatus, it is possible to prevent supply to the capacitor 87 of charge in an amount in excess of an allowable amount, which supply would otherwise been effected at the time of interruption of spark discharge.