PURPOSE: To provide an additional foot for a ladder which foot can be fastened either to the right side of ladder supports or to the left side thereof.

CONSTITUTION: The width of a fastening member 1 is made slightly wider than a width A of a ladder support 5 and the depth of the fastening member 1 is made wider, by the thickness of a wedge 3, than a depth B thereof. The fastening member 1 is put on the ladder support 5, and is fastened thereto by driving the wedge 3 into a clearance between its front plate and the front of the support 5. An additional foot therefor is made the same as an interval between the lowest step of a ladder or the undersurface of a rung 6 in the second step from the bottom and the lower end of the ladder support 5, or is made slightly shorter than the interval.