To reduce exhaust gas, prevent generation of white smoke while improving engine stability during cold/warm-up operation of a diesel engine, and to improve heater performance during cold/warm-up operation.

An engine combustion temperature is controlled by means of an EGR device according to engine operation conditions. An ignition retarding timing in fuel injection is controlled by controlling the fuel injection timing in an operation area where the combustion temperature is lowered. In addition, swirl is generated in the combustion chamber. The cooling water temperature of the engine is sensed at this time. The combustion temperature, that is an EGR amount is corrected according to the cooling water temperature. In addition, the ignition retarding timing, that is, the injection timing is corrected. Intensity of the swirl is also corrected. Gradual initial combustion and abrupt combustion thereafter can be obtained both, even under cold/warm-up operation.