An internal combustion engine of a compressed self-ignition type that performs combustion by injecting fuel into a compressed combustion chamber, the internal combustion engine comprising: a fuel injection nozzle provided with a nozzle hole for injecting fuel, the nozzle hole exposed from a cylinder head of the internal combustion engine to the combustion chamber; the fuel injection nozzle further including a body including the nozzle hole at a tip end portion and a needle valve that is housed in a manner capable of moving along an axial direction inside the body; and a hollow duct, an inlet and an outlet of which are exposed to the combustion chamber, wherein the duct is provided in a manner allowing fuel spray injected from the nozzle hole of the fuel injection nozzle to pass through from the inlet to the outlet, the fuel injection nozzle and the duct are configured such that a part of fuel spray that is injected from the nozzle hole in pilot injection that is performed before main injection directly adheres to an inner wall surface of the duct, the fuel injection nozzle is configured such that a spray angle of the fuel spray that is injected from the nozzle hole is adjustable, wherein the spray angle is a spreading angle of the fuel spray, and the fuel injection nozzle is adjusted to a spray angle at which a part of the fuel spray that is injected from the nozzle hole in the pilot injection directly adheres to the inner wall surface of the duct, characterized in that the internal combustion engine further comprises a control device that adjusts an amount of fuel adhesion of fuel that directly adheres to the duct in the pilot injection, wherein the control device is configured to acquire an index value that serves as an index for a temperature of the duct, and in a case where the index value is in a region corresponding to a high-temperature region of the temperature of the duct, to increase the amount of fuel adhesion compared to a case where the index value is in a region corresponding to a low-temperature region, wherein the fuel injection nozzle further includes an actuator that adjusts an amount of lift of the needle valve from a seated position, wherein the fuel injection nozzle increases the spray angle of fuel injection from the nozzle hole as the amount of lift of the needle valve from the seated position becomes smaller, and the control device is configured to operate the actuator according to the index value. a fuel injection nozzle provided with a nozzle hole for injecting fuel, the nozzle hole exposed from a cylinder head of the internal combustion engine to the combustion chamber; the fuel injection nozzle further including a body including the nozzle hole at a tip end portion and a needle valve that is housed in a manner capable of moving along an axial direction inside the body; and a hollow duct, an inlet and an outlet of which are exposed to the combustion chamber, wherein the duct is provided in a manner allowing fuel spray injected from the nozzle hole of the fuel injection nozzle to pass through from the inlet to the outlet, the fuel injection nozzle and the duct are configured such that a part of fuel spray that is injected from the nozzle hole in pilot injection that is performed before main injection directly adheres to an inner wall surface of the duct, the fuel injection nozzle is configured such that a spray angle of the fuel spray that is injected from the nozzle hole is adjustable, wherein the spray angle is a spreading angle of the fuel spray, and the fuel injection nozzle is adjusted to a spray angle at which a part of the fuel spray that is injected from the nozzle hole in the pilot injection directly adheres to the inner wall surface of the duct, characterized in that the internal combustion engine further comprises a control device that adjusts an amount of fuel adhesion of fuel that directly adheres to the duct in the pilot injection, wherein the control device is configured to acquire an index value that serves as an index for a temperature of the duct, and in a case where the index value is in a region corresponding to a high-temperature region of the temperature of the duct, to increase the amount of fuel adhesion compared to a case where the index value is in a region corresponding to a low-temperature region, to acquire an index value that serves as an index for a temperature of the duct, and in a case where the index value is in a region corresponding to a high-temperature region of the temperature of the duct, to increase the amount of fuel adhesion compared to a case where the index value is in a region corresponding to a low-temperature region, wherein the fuel injection nozzle further includes an actuator that adjusts an amount of lift of the needle valve from a seated position, wherein the fuel injection nozzle increases the spray angle of fuel injection from the nozzle hole as the amount of lift of the needle valve from the seated position becomes smaller, and the control device is configured to operate the actuator according to the index value.