SPARK IGNITION INTERNAL COMBUSTION ENGINE

The problem to be solved by the present invention is to reduce the emission of the unburned fuel and to improve fuel efficiency of the internal combustion engine in a spark ignition type internal combustion engine that allows an electric field created in a combustion chamber to react with a spark discharge by an ignition plug and generates plasma, thereby igniting fuel air mixture. The present invention is directed to the spark ignition type internal combustion engine that allows the spark discharge by the ignition plug to react with the electric field created in the combustion chamber and generates the plasma, thereby igniting the fuel air mixture including: an electromagnetic wave emission device that emits an electromagnetic wave in the combustion chamber when the fuel air mixture is combusted; and a protruding member protruding from a partitioning surface that partitions the combustion chamber, wherein at least a part of the protruding member is made of a conductor.