To provide a step ladder in which a step plate can be easily replaced, and in which resources or material is less wasted.

This step ladder comprises a plurality of cleat plates 9 combined with each other, and a frame part 10 containing and holding the cleat plates 9. The cleat plates 9 are combined on each other to form a step body 8 on which passengers step on. For the step body 8, screw rods 15 and 15a are inserted to installation holes 11 and 11a in the cleat plates 9 and installation holes 13 and 13a provided in the frame part 10 to be tightened to installation holes 14 and 14a provided in the frame part 10. The screw rods 15 and 15a are thus fixed to the frame part 10. The cleat plates 9 are thus securely contained and held to the frame part 10 in such a way that their plate end parts 9a form cleat step faces.