PURPOSE: To provide a large engine brake torque when rotating speed is high in an intake air quantity control unit for internal combustion engine having a throttle valve driving device for opening and closing a throttle valve by a throttle link provided separately from a throttle link connected to an accelerator pedal.

CONSTITUTION: When a brake switch 17 is ON (BK='1.) (step 301), it is judged whether the rotating speed Ne determined by a crank angle sensor 6 is small or large (step 302). When the rotating speed Ne is small, consequently, a throttle valve 8 is fully opened (step 303), and when the rotating speed Ne is conversely large, the throttle valve 8 is fully opened (step 304).