An internal combustion engine having an independent combustion chamber comprises a combustion chamber (1), an air inlet system (2), a material feeding system (3), and a working system (4). The air inlet system (2) and the combustion chamber (1) are connected together and configured to transport a compressed air to the combustion chamber (1). The material feeding system (3) and the combustion chamber (1) are connected together and configured to transport a fuel to the combustion chamber (1). The combustion chamber (1) has a fixed volume and has no movable wall such as a piston. The fuel continues to be burned in the combustion chamber (1) to generate a high-temperature and high-pressure gas, and chemical energy of the fuel is converted into internal energy of the high-temperature and high-pressure gas. The working system (4) and the combustion chamber (1) are connected together. The piston (21) of the working system (4) works to convert the internal energy of the gas into a mechanical energy.