An internal combustion engine comprises a main combustion chamber part, an auxiliary combustion chamber part, a first communicating passage, a second communicating passage and an igniting component. The auxiliary combustion chamber part includes first and second auxiliary combustion chambers. The first auxiliary combustion chamber is disposed adjacent to the main combustion chamber part. The second auxiliary combustion chamber is disposed adjacent to the first auxiliary combustion chamber at a position further away from the main combustion chamber part. The first communicating passage extends between the main combustion chamber part and the first auxiliary combustion chamber and the second communicating passage extends between the first auxiliary combustion chamber and the second auxiliary combustion chamber. The ignition component is configured and arranged to ignite fresh air-fuel mixture introduced from the main combustion chamber into the first auxiliary combustion chamber through the first communicating passage.