Combustion system of the diesel engine

PROBLEM TO BE SOLVED: To provide the constitution for obtaining an improving effect of exhaust gas by injecting fuel in a multistage without forming a fuel injection nozzle such as a complcated structure when adopting a shallow pan-shaped combustion chamber. SOLUTION: This combustion system of a diesel engine has the combustion chamber arranged in a top surface part of a piston reciprocatably arranged in a cylinder, and having a bottom wall part and a side wall part gradually diametrally expanding toward a top surface of the piston from the outer peripheral end of the bottom wall part, and a fuel injector capable of injecting the fuel in a multistage toward the combustion chamber, and is characterized in that the fuel injector has a fuel injection nozzle having a fuel injection angle for injecting fuel toward the vicinity of a connecting part of the bottom wall part and the side wall part of the combustion chamber when the piston exists in the vicinity of the compression upper dead center, and injects the fuel as a first stage when the piston exists in the vicinity of the compression upper dead center, and the, injects it as a second stage toward the combustion chamber when the piston exists in a lowered position more than the fuel injection timing of the first stage.