In a compression ignition internal combustion engine 20that generates electromagnetic wave plasma by emitting electromagnetic waves to a combustion chamber 21 during a period of a preceding injection, a control device 10 for internal combustion engine controls a fuel injection device 24 to perform, before a main injection, a preceding injection less in injection quantity than the main injection, while controlling a plasma generation device 30 to generate electromagnetic plasma by emitting electromagnetic waves to the combustion chamber 21 during the period of the preceding injection. The control device 10 controls a condition of heat production due to combustion of fuel from the main injection by controlling the amount of energy of the electromagnetic waves emitted to the combustion chamber 21 during the period of the preceding injection according to the operating condition of the internal combustion engine main body 22.