A control apparatus for an internal combustion engine starts the internal combustion engine by initiating combustion in cylinders belonging to a first cylinder group, from among a plurality of cylinders that make up the internal combustion engine. The control apparatus monitors a change in an amount of negative pressure generated in an intake pipe when the internal combustion engine is started, and obtains information related to an alcohol concentration of fuel used in the internal combustion engine. The control apparatus also calculates a fuel injection quantity necessary to initiate combustion in cylinders belonging to a second cylinder group, based on the amount of negative pressure generated in the intake pipe and the alcohol concentration of the fuel, and initiates combustion in each cylinder belonging to the second cylinder group when the necessary fuel injection quantity enters a range of quantities that are able to be injected by corresponding injectors.