To restrain drivability from being worsened caused by improper execution in torque control for regulating leading of engine torque when an internal combustion engine transits from an idling condition to an off-idling condition.

When a gas flow control valve 48 is switched from a valve- closed condition to a valve-opened condition in accompaniment to the transition from the idling condition to the off-idling condition in a homogeneous charge combustion operation, the opened and closed conditions of the control valve 48 are switched after the torque control is finished, when the torque control is under execution to restrain torque shock accompanied to switching from a nonengaged condition to an engaged condition of a unidirectional clutch 3 in an automatic transmission 2. Thereby, the opened and closed conditions of the control valve 48 are switched during the torque control to restrain the opening and closing of the control valve 48 from being interfered by the torque control.