Controller of internal combustion engine

A controller of an internal combustion engine having intake throttle valves in branch intake passages of respective cylinders for regulating intake air quantities, the branch intake passages branching from a main intake passage of the engine for introducing the intake air into the respective cylinders, the controller comprising:

• an intake air quantity sensor provided in the main intake passage for sensing the intake air quantity;
• a low opening degree control device that performs low opening degree control for controlling an opening degree of the intake throttle valve during a first intake stroke period since an engine start is commenced until first intake strokes of the respective cylinders end such that intake pressure downstream of the intake throttle valve becomes pressure equal to or lower than predetermined critical pressure with respect to intake pressure upstream of the intake throttle valve during the intake stroke of each cylinder;
• a leak air quantity calculation device that calculates a leak air quantity at the time when the intake throttle valve is fully closed based on the intake air quantity sensed with the intake air quantity sensor during the low opening degree control;
• and
• an intake throttle valve opening degree correction device that corrects the opening degree of the intake throttle valve in accordance with the leak air quantity.