To further properly set ignition timing at the start of the internal combustion engine.

When an engine is started by motoring a first engine (S120, S160), the engine is controlled at an ignition timing according to the driving state of whether the engine reaches a complete combustion or not by masking a knock determining result (S180 to S210) until a predetermined time tref1 is passed from the start of the engine. It is controlled at an ignition timing according to the driving state and the knock determination result (S210, S220) after a predetermined time tref1 is passed from the start of the engine. Thereby, the ignition is controlled without the rotational speed Ne of the engine by motoring and a wrong knock determination result due to the rapid change of intake pressure, so that the ignition timing at a time of start of the engine can be more properly set.