To provide a pedal supporting structure capable of preventing misoperation and exhibiting excellent operatability for a tractor having both of advancing and retreating pedals and left and right brake pedals.

Both of the advancing pedal 30 and the retreating pedal 31 are installed on a floor 2, and both of the left and right brake pedals 4L and 4R for braking rear wheels at left and right are installed over them. In order to install the both kinds of the pedals adjacently vertically, the left and right brake pedals 4L and 4R are located apart from one of the advancing and retreating pedals 30 and 31 along the lateral direction. Further, the pedals are set so that the stepping surface of the pedals 4L and 4R and the stepping surface of the advancing pedal 30 or the retreating pedal 31 is on an almost a same surface when the brake pedal 4L or 4R is stepped on.