In a homogeneous charge compression-ignited internal-combustion engine, based on information regarding the operational state of the engine, a combustion mode switching discriminator selects a homogeneous charge compression-ignited combustion mode if engine operating conditions allow homogeneous charge compression-ignited combustion. If not, the combustion mode switching discriminator selects a spark-ignited combustion mode. Immediately after switching from spark-ignited combustion to homogeneous charge compression-ignited combustion, a combustion mode switching corrector outputs switching correction values for operating quantities for homogeneous charge compression-ignited combustion. The correction values are used to adjust the operating quantities for homogeneous charge compression-ignited combustion, and new operating quantities obtained from the adjustments are output as control quantities from a combustion mode selector.