PURPOSE: To prevent an accident because of erroneous operation by instantaneously stopping an acceleration pedal when the acceleration pedal of an automobile is unexpectedly depressed by mistaking it for a brake pedal.

CONSTITUTION: A base part of an acceleration pedal lever 3 is pivoted to an acceleration arm 1 and semi-fixed members, which are separated from each other in the case where specific downward impulsive force is exerted, are fitted to opposing positions of the acceleration arm 1 and the acceleration lever 3, respectively. A stopper 10 is provided for locking a lowering position of the acceleration pedal lever 3 at a predetermined position and a buffer member 12 is arranged on the acceleration pedal lever 3 or on a floor.