To provide a multiple discharge type ignition device having an ion current detection circuit which does not require a power supply circuit nor a filter circuit from a primary side by controlling a voltage generated on a secondary side to a negative voltage at the completion of discharge.

An ignition device is equipped with a plurality of switching elements for primary coil drive. The switching element forms a push-pull circuit by on-off control by a control part. The device alternately executes multiple ignition by turning on/off a plurality of switching elements at one ignition timing. An ion current detection circuit is provided at the secondary coil side. A discharge polarity is determined at the time of a trigger input when the discharge is completed so as to complete the discharge at a secondary output voltage of a negative polarity.