A second pedal bracket 25 that supports a brake pedal 11 by a pedal support shaft 27 is swingably connected, via a bracket support shaft 28, to an upper part of a first pedal bracket 20 fixed to a dashpanel 3. Both the first and second pedal brackets 20 and 25 and a restricting/derestricting member 32 are connected to each other by a bolt 37 to restrict swinging of the second pedal bracket 25. Upon collision of an automobile, a rear end wall 39 of the restricting/derestricting member 32 abuts against an instrument member 7, thus moving the member 32 and bolt 37 relatively forward to derestrict the second pedal bracket 25. Then, an arm 40 extended upward from the second pedal bracket 25 abuts against the instrument member 7, thus rotating the second pedal bracket 25 to displace the pedal support shaft 27 backward.