PURPOSE: To reduce complication of speed change control and shift shock by providing a control means for controlling intake air quantity control means which does not allow the opening degree of the intake air quantity control means to follow the opening degree of accelerator during the speed change operation of an automatic transmission control means.

CONSTITUTION: An accelerator opening detection means 2 measures the pressing down quantity of accelerator pedal 1. A throttle valve 4 controls the intake air quantity of an engine 5. An output shaft rotating speed detection means 9 detects the output shaft rotating speed of an automatic transmission 8. An automatic transmission controller 11 controls the automatic transmission 8. During the speed change operation of the controller 11 the opening degree of throttle is constant even if the opening degree of accelerator changes and especially when a speed change flag is cleared the opening degree of throttle is changed to the quantity corresponding to the accelerator opening degree at that time. The complication of speed change control can be omitted and shift shock is reduced in this way.