PURPOSE: To control the combustion of an internal combustion engine in a combustion condition where low NOx and combustion stability are balanced at a high level by calculating combustion start timing and combustion period based on the detected signal of a sensor, and controlling the ignition timing and fuel infection amount so that the combustion start timing and the combustion period meet their target.

CONSTITUTION: This combustion controller is provided with a crank angle sensor 46 which detects the rotational angle of a crankshaft 14 in an internal combustion engine 2, and an in-cylinder pressure sensor 48 which detects the pressure of a combustion chamber 16 in the internal combustion engine 2. A control part 50 calculates combustion start timing and combustion period based on the detected signals of the crank angle sensor 46 and the in-cylinder pressure sensor 48, and controls ignition timing and fuel injection amount so that the combustion start timing and the combustion period meet their targets respectively. It is thus possible to control the combustion of an internal combustion engine in a combustion condition where low NOx and combustion stability are balanced at a high level.