In order to reduce the bulk and weight of the upper igniter case division of the armor case, and to lower the center of gravity of the total apparatus so as to provide an igniter which is tough to oscillate, the igniter for the internal combustion engine has the armor case equipped with the coil department and igniter unit therein, and said armor case has the igniter case having the coil department case and the connector department. Furthermore, the coil department case is inserted in the plug hole of the internal combustion engine. The igniter unit is mounted in the igniter case. Furthermore, the igniter unit has a semiconductor device of a simple substance silicon chip having integrated therein a semi-conductor for switching and a current limiting circuitry. The semi-conductor for switching consists of an insulated bipolar transistor (IGBT) or a power transistor.