The automobile pedal supporting structure includes a first bracket 5, the front end of the first bracket 5 being fixed on a dash panel 1, and the rear end of the first bracket 5 being fixed on a vehicle-side member 8 which is more rigid than the dash panel 1 so that the first bracket 5 can be removed from the vehicle-side member 8, and a second bracket 6, the front-end lower part of the second bracket 6 being pivotally attached to the first bracket 5 so that the second bracket 6 can swing, the rear-end upper part of the second bracket 6 being fixed on the vehicle-side member 8 so that the second bracket 6 can be removed from the vehicle-side member 8, and an operation pedal 4 being pivotally attached to the second bracket 6 so that the operation pedal 4 can swing, in which the first bracket 5 and the second bracket 6 are placed to substantially overlap each other, the rear-end upper part of the second bracket 6 are fixed together with the first bracket 5 on the vehicle-side member 8, and a turn promoting member 12 is provided, which is connected from the vehicle-side member 8 through the rear-end outside of the first bracket 5 to the upper part of the second bracket 6 and promotes a turn of the second bracket 6 toward the vehicle-lower side by a backward movement of the first bracket 5 toward the vehicle-rear side.