A homogeneous charge compression ignition engine includes a combustion chamber
and a piston for compressing and igniting an air-fuel mixture in the combustion
chamber. A variable valve actuation mechanism opens and closes an exhaust valve
to perform internal exhaust gas recirculation. A heater heats the mixture before
the mixture is supplied to the combustion chamber. A storage device stores correspondence
information of the amount of internal exhaust gas recirculation and heated state
of the mixture heated by the heater that are necessary to perform homogeneous charge
compression ignition in relation with the load of the engine and the rotation speed
of the output shaft. A controller controls the variable valve actuation mechanism
and the heater to achieve the amount of internal exhaust gas recirculation and
heated state of the mixture in correspondence with the load and speed required
for the engine.