Abstract: An engine system includes a combustion chamber and an air supplier. The combustion chamber is formed in a cylinder. The air supplier is configured to supply air to a circumferential area of the combustion chamber. The circumferential area is near an inner circumferential surface of the cylinder. The air supplier is configured to supply air to the circumferential area before ignition to gather a rich air-fuel mixture that is present in the combustion chamber to a central area of the combustion chamber such that a stratified body consisting of a layer of the air-fuel mixture in the central area and a layer of the air in the circumferential area is formed.