The invention provides an engine control device which is provided with a judging part which can judge a state that a vehicle is not driven, a
brake torque gaining part which drives and acts on the
brake torque of the vehicle, a vehicle speed detection part used for detecting the vehicle speed, and an
atmospheric pressure gaining part which gains the
atmospheric pressure value when the engine is driven. The engine control device calculates the slope of the
road surface by a
road surface slope judging part according to the
brake torque gained by the
brake torque gaining part and the vehicle speed detected by the vehicle speed detection part when in the state that the vehicle is not driven judged by the judging part, calculates the descending height of the vehicle according to the calculated slope of the
road surface and the driving distance calculated through the vehicle speed, corrects the
atmospheric pressure value gained by the atmospheric pressure gaining part, and masters the atmospheric at the position of the
downgrade of the vehicle. The engine control device aims at calculating the slope of the road surface according to the
brake torque acted on the vehicle and the vehicle speed in the engine control device without an atmospheric sensor, calculating the descending height of the
downgrade of the vehicle according to the slope of the road surface, correcting the atmospheric value according to the descending height, mastering the atmospheric at the position of the
downgrade of the vehicle, thus leading the openness of an electronic control
throttle valve to be proper and improving driving performance.