A discharge control unit causes a high voltage to be generated in a secondary coil by controlling an igniter unit so as to block a flow of current from a primary coil towards a ground side, and controls a spark plug so that electric discharge is formed between electrodes of the spark plug. An energy input control unit controls an energy input unit to input electrical energy to an ignition coil after start of control of the spark plug by the discharge control unit. A normal ignition control unit controls ignition of an air-fuel mixture in a combustion chamber only through control of the spark plug by the discharge control unit. A specific ignition control unit controls the ignition of the air-fuel mixture in the combustion chamber through control of the spark plug by the discharge control unit and through control of the energy input unit by the energy input control unit. A control unit performs ignition control by the specific ignition control unit until a first predetermined period elapses after a start-up condition of an engine is established, and switches to ignition control by the normal ignition control unit after the elapse of the first predetermined period.