To provide a step for a loading space of a truck, which enables a gate of the loading space of the truck to be safely self-supported with no slip, even if the gate is set in state of being horizontally brought down, which can increase the load bearing strength of the gate by making the horizontally-brought-down gate supported by a ladder serving as a supporting leg for the gate, and which is excellent in the property of storage of the step in the loading space of the truck in nonuse.

This step for the ascent to/the descent from the loading space of the truck serves as the ladder which is used by being set in a required place in the loading space of the truck. Upper and lower fittings 7 and 8, which sandwich a round end of the horizontally-brought-down gate of the loading space of the truck from above and below, are provided for supports 1 and 1 of the ladder 3 in which rungs 3a are mounted at proper intervals on the pair of supports 1 and 1 on both sides, respectively. An upper or lower holding piece 44 or 61, which can be freely rotated so that either or both of the upper and lower fittings 7 and 8 can be folded along the supports 1 and 1, is or are journaled on the supports 1 and 1. A rotation stopper 54 or 55 journaled on the supports 1 and 1 can be engaged with the upper or lower holding piece 44 or 61.